diff --git a/calendar.go b/calendar.go
index b3ebeb2..7c96a59 100644
--- a/calendar.go
+++ b/calendar.go
@@ -12,8 +12,7 @@ import (
 	"mujicaui/theme"
 )
 
-// WeekStart is the first column of a month. The zero value follows the locale:
-// Monday for zh-CN, Sunday for en-US.
+// WeekStart is a month's first column; zero follows the locale.
 type WeekStart int
 
 const (
@@ -25,7 +24,7 @@ const (
 
 // CalendarOptions configure a Calendar.
 type CalendarOptions struct {
-	// Min and Max bound the days that can be chosen; zero leaves a side open.
+	// Min and Max bound choosable days; zero is open.
 	Min, Max Date
 	// DisableDate marks single days that cannot be chosen.
 	DisableDate func(Date) bool
@@ -38,7 +37,6 @@ type CalendarOptions struct {
 }
 
 // Calendar shows one month and chooses a day into *value.
-// Arrows move by day and week, PageUp/PageDown by month, Shift with them by year.
 func Calendar(c *ui.Context, value *Date, opts CalendarOptions) DateTimeResult {
 	datetimeCheckDate("Calendar value", *value)
 	datetimeCheckBounds("Calendar", opts.Min, opts.Max)
@@ -115,7 +113,7 @@ func calendarSeek(d Date, dir int, enabled func(Date) bool) Date {
 	return d
 }
 
-// calendarMonth draws the month of *cursor and returns the day picked and the day hovered.
+// calendarMonth draws *cursor's month; returns picked and hovered days.
 func calendarMonth(c *ui.Context, cursor *Date, cfg calendarConfig) (picked, hovered Date) {
 	k := Tokens(c)
 	d := Density(c)
@@ -140,7 +138,7 @@ func calendarMonth(c *ui.Context, cursor *Date, cfg calendarConfig) (picked, hov
 			if datetimeIconButton(c, "chevron-left", msg(c, "calendar.prev_month")).Clicked() {
 				move(cur.AddMonths(-1), -1, false)
 			}
-			ui.Text(c, title).Font(theme.SerifFont).FontSize(theme.BodySize + 2).Bold().
+			ui.Text(c, title).Font(theme.SerifFont).FontSize(FontSize(c, theme.BodySize+2)).Bold().
 				TextColor(k.Text).Grow(1).TextAlign(ui.Center).SingleLine()
 			if datetimeIconButton(c, "chevron-right", msg(c, "calendar.next_month")).Clicked() {
 				move(cur.AddMonths(1), 1, false)
@@ -154,7 +152,7 @@ func calendarMonth(c *ui.Context, cursor *Date, cfg calendarConfig) (picked, hov
 			for i := range 7 {
 				wd := (int(first) + i) % 7
 				ui.Text(c, msg(c, "calendar.weekday_"+strconv.Itoa(wd))).Width(cell).TextAlign(ui.Center).
-					FontSize(theme.CaptionSize).TextColor(k.TextMuted).Role(ui.RoleColumnHeader).
+					FontSize(FontSize(c, theme.CaptionSize)).TextColor(k.TextMuted).Role(ui.RoleColumnHeader).
 					Label(msg(c, "calendar.weekday_long_"+strconv.Itoa(wd)))
 			}
 		})
diff --git a/date_picker.go b/date_picker.go
index c17fe93..d0630a5 100644
--- a/date_picker.go
+++ b/date_picker.go
@@ -24,12 +24,13 @@ type DatePickerOptions struct {
 	// Placeholder shows in the empty field; empty uses the built-in copy.
 	Placeholder string
 	Disabled    bool
+	// ReadOnly keeps the text focusable and copyable but blocks edits and the popup.
+	ReadOnly bool
 	// Label names the field for assistive technology.
 	Label string
 }
 
-// DatePicker is a typed date field with a calendar popup editing *value.
-// Typed text commits on Enter or when the field loses focus; invalid text stays and is reported.
+// DatePicker types or picks *value; invalid text is kept and reported.
 func DatePicker(c *ui.Context, value *Date, opts DatePickerOptions) DateTimeResult {
 	datetimeCheckDate("DatePicker value", *value)
 	datetimeCheckBounds("DatePicker", opts.Min, opts.Max)
@@ -53,6 +54,13 @@ func DatePicker(c *ui.Context, value *Date, opts DatePickerOptions) DateTimeResu
 	open := ui.Local(col, "date-picker-open", func() bool { return false })
 	cursor := ui.Local(col, "date-picker-cursor", func() Date { return Date{} })
 	wasFocused := ui.Local(col, "date-picker-focused", func() bool { return false })
+	shownLayout := ui.Local(col, "date-picker-layout", func() string { return layout })
+	if *shownLayout != layout {
+		if *text == Date.Format(*value, *shownLayout) || value.IsZero() && *text == "" {
+			*text = format(*value)
+		}
+		*shownLayout = layout
+	}
 	if *seen != *value {
 		*seen, *text, *problem = *value, format(*value), ""
 	}
@@ -96,23 +104,26 @@ func DatePicker(c *ui.Context, value *Date, opts DatePickerOptions) DateTimeResu
 	}
 	var field *ui.Element
 	col.Children(func() {
-		field = datetimeField(c, ui.Row(c), *problem != "")
+		field = datetimeField(c, ui.Row(c), *problem != "", opts.ReadOnly)
 		field.Children(func() {
-			in := ui.TextInputBase(c, text).Grow(1).Shrink(1).Placeholder(placeholder).FontFeatures("tnum")
+			in := textInputEditor(c, field, text, opts.ReadOnly, false).Grow(1).Shrink(1).Placeholder(placeholder).FontFeatures("tnum")
 			label := opts.Label
 			if label == "" {
 				label = placeholder
 			}
 			in.Label(label).Error(*problem)
 			focused := in.Focused()
-			if in.Submitted() || *wasFocused && !focused && *text != format(*value) {
+			if !opts.ReadOnly && (in.Submitted() || *wasFocused && !focused && *text != format(*value)) {
 				submit()
 			}
 			*wasFocused = focused
+			if opts.ReadOnly {
+				return
+			}
 			if opts.Clearable && !value.IsZero() && datetimeIconButton(c, "x", msg(c, "calendar.clear")).Clicked() {
 				commit(Date{}, "clear")
 			}
-			if datetimeIconButton(c, "calendar", msg(c, "date_picker.open")).Clicked() {
+			if datetimeIconButton(c, "calendar", msg(c, "date_picker.open")).Role(ui.RolePopUpButton).Clicked() {
 				if *open {
 					*open = false
 				} else {
@@ -120,10 +131,10 @@ func DatePicker(c *ui.Context, value *Date, opts DatePickerOptions) DateTimeResu
 				}
 			}
 		})
-		if !*open && (field.Shortcut(0, ui.KeyDown) || field.Shortcut(ui.Alt, ui.KeyDown)) {
+		if !*open && !opts.ReadOnly && (field.Shortcut(0, ui.KeyDown) || field.Shortcut(ui.Alt, ui.KeyDown)) {
 			openAt()
 		}
-		datetimePopup(c, field, open, func() {
+		datetimePopup(c, field, open, opts.ReadOnly, func() {
 			picked, _ := calendarMonth(c, cursor, calendarConfig{
 				chosen:    func(x Date) bool { return x == *value },
 				enabled:   enabled,
diff --git a/date_range_picker.go b/date_range_picker.go
index 0ce0323..096e95b 100644
--- a/date_range_picker.go
+++ b/date_range_picker.go
@@ -37,12 +37,13 @@ type DateRangePickerOptions struct {
 	// Today is marked in the calendar; zero uses the system clock.
 	Today    Date
 	Disabled bool
+	// ReadOnly keeps the field focusable and copyable but blocks the popup.
+	ReadOnly bool
 	// Label names the field for assistive technology.
 	Label string
 }
 
-// DateRangePicker edits *value in a popup: pick a start, preview the span, pick an end, then confirm.
-// Clear empties the value; Escape, Cancel or a click outside discards the draft.
+// DateRangePicker picks start and end; Confirm writes *value.
 func DateRangePicker(c *ui.Context, value *DateRange, opts DateRangePickerOptions) DateTimeResult {
 	datetimeCheckDate("DateRangePicker Start", value.Start)
 	datetimeCheckDate("DateRangePicker End", value.End)
@@ -84,10 +85,10 @@ func DateRangePicker(c *ui.Context, value *DateRange, opts DateRangePickerOption
 	}
 	var field *ui.Element
 	col.Children(func() {
-		field = datetimeField(c, ui.Row(c), false)
+		field = datetimeField(c, ui.Row(c), *problem != "", opts.ReadOnly)
 		field.Children(func() {
-			t := datetimeTrigger(c, text, msg(c, "date_range_picker.placeholder"), "calendar").Label(label).Description(text)
-			if t.Clicked() || !*open && t.Shortcut(0, ui.KeyDown) {
+			t := datetimeTrigger(c, text, msg(c, "date_range_picker.placeholder"), "calendar").Label(label).Description(text).Error(*problem)
+			if !opts.ReadOnly && (t.Clicked() || !*open && t.Shortcut(0, ui.KeyDown)) {
 				*open = !*open
 				if *open {
 					*draft, *problem, *hover = *value, "", Date{}
@@ -99,9 +100,9 @@ func DateRangePicker(c *ui.Context, value *DateRange, opts DateRangePickerOption
 				}
 			}
 		})
-		datetimePopup(c, field, open, func() {
+		datetimePopup(c, field, open, opts.ReadOnly, func() {
 			ui.Text(c, dateRangeSummary(c, *draft, layout)).TextColor(k.TextMuted).
-				FontSize(theme.CaptionSize).FontFeatures("tnum").Role(ui.RoleStatus)
+				FontSize(FontSize(c, theme.CaptionSize)).FontFeatures("tnum").Role(ui.RoleStatus)
 			end := draft.End
 			if end.IsZero() && !draft.Start.IsZero() {
 				end = *hover
@@ -144,6 +145,9 @@ func DateRangePicker(c *ui.Context, value *DateRange, opts DateRangePickerOption
 		cancelled = true
 	}
 	*wasOpen = *open
+	if !*open {
+		*problem = ""
+	}
 	return DateTimeResult{Element: col, changed: changed, cancelled: cancelled}
 }
 
diff --git a/date_time_picker.go b/date_time_picker.go
index b5c60ce..9e7c482 100644
--- a/date_time_picker.go
+++ b/date_time_picker.go
@@ -12,8 +12,10 @@ import (
 
 // DateTimePickerOptions configure a DateTimePicker.
 type DateTimePickerOptions struct {
-	// Location is the time zone the user edits in. Required.
+	// Location is the time zone the user edits in; required.
 	Location *time.Location
+	// Layout is the Go layout of the date part; empty uses 2006-01-02.
+	Layout string
 	// Min and Max bound the instant; zero leaves a side open.
 	Min, Max   time.Time
 	Seconds    bool
@@ -23,12 +25,13 @@ type DateTimePickerOptions struct {
 	// Today is marked in the calendar; zero uses the system clock.
 	Today    Date
 	Disabled bool
+	// ReadOnly keeps the field focusable and copyable but blocks the popup.
+	ReadOnly bool
 	// Label names the field for assistive technology.
 	Label string
 }
 
-// DateTimePicker edits *value as a date and a wall-clock time in opts.Location, confirmed together.
-// Times a DST change skips or repeats are reported, never shifted.
+// DateTimePicker edits *value as wall time in opts.Location.
 func DateTimePicker(c *ui.Context, value *time.Time, opts DateTimePickerOptions) DateTimeResult {
 	loc := opts.Location
 	if loc == nil {
@@ -56,7 +59,11 @@ func DateTimePicker(c *ui.Context, value *time.Time, opts DateTimePickerOptions)
 	clock := ui.Local(col, "date-time-clock", func() TimeOfDay { return TimeOfDay{} })
 	cursor := ui.Local(col, "date-time-cursor", func() Date { return Date{} })
 	problem := ui.Local(col, "date-time-error", func() string { return "" })
-	format := func(t time.Time) string { return dateTimeText(c, t.In(loc), cfg) }
+	typedBad := ui.Local(col, "date-time-typed-bad", func() bool { return false })
+	if opts.Layout == "" {
+		opts.Layout = "2006-01-02"
+	}
+	format := func(t time.Time) string { return dateTimeText(c, t.In(loc), opts.Layout, cfg) }
 	changed, cancelled, done := false, false, false
 	label := opts.Label
 	if label == "" {
@@ -67,10 +74,10 @@ func DateTimePicker(c *ui.Context, value *time.Time, opts DateTimePickerOptions)
 		text = format(*value)
 	}
 	col.Children(func() {
-		field := datetimeField(c, ui.Row(c), false)
+		field := datetimeField(c, ui.Row(c), *problem != "", opts.ReadOnly)
 		field.Children(func() {
-			t := datetimeTrigger(c, text, msg(c, "date_time_picker.placeholder"), "calendar").Label(label).Description(text)
-			if t.Clicked() || !*open && t.Shortcut(0, ui.KeyDown) {
+			t := datetimeTrigger(c, text, msg(c, "date_time_picker.placeholder"), "calendar").Label(label).Description(text).Error(*problem)
+			if !opts.ReadOnly && (t.Clicked() || !*open && t.Shortcut(0, ui.KeyDown)) {
 				*open = !*open
 				if *open {
 					*day, *clock, *problem = today, TimeOfDay{}, ""
@@ -83,7 +90,7 @@ func DateTimePicker(c *ui.Context, value *time.Time, opts DateTimePickerOptions)
 				}
 			}
 		})
-		datetimePopup(c, field, open, func() {
+		datetimePopup(c, field, open, opts.ReadOnly, func() {
 			picked, _ := calendarMonth(c, cursor, calendarConfig{
 				chosen:    func(x Date) bool { return x == *day },
 				enabled:   calendarEnabled(lo, hi, nil),
@@ -94,11 +101,17 @@ func DateTimePicker(c *ui.Context, value *time.Time, opts DateTimePickerOptions)
 			if !picked.IsZero() {
 				*day, *problem = picked, ""
 			}
+			bad := ""
 			ui.Row(c).Gap(d.Unit() * 2).AlignItems(ui.Center).Children(func() {
-				if _, edited := timeEditor(c, clock, cfg); edited {
-					*problem = ""
+				cfg.problem = *problem
+				_, edited, b := timeEditor(c, clock, cfg)
+				switch {
+				case b != "":
+					*problem, *typedBad, bad = b, true, b
+				case edited || *typedBad:
+					*problem, *typedBad = "", false
 				}
-				ui.Text(c, loc.String()).FontSize(theme.CaptionSize).TextColor(k.TextMuted)
+				ui.Text(c, loc.String()).FontSize(FontSize(c, theme.CaptionSize)).TextColor(k.TextMuted)
 			})
 			datetimeError(c, *problem)
 			datetimeFooter(c, func() {
@@ -107,6 +120,9 @@ func DateTimePicker(c *ui.Context, value *time.Time, opts DateTimePickerOptions)
 				}
 				if Button(c, msg(c, "calendar.confirm"), ButtonOptions{}).Clicked() {
 					at, p := dateTimeConfirm(c, *day, *clock, loc, opts, cfg)
+					if bad != "" {
+						p = bad
+					}
 					*problem = p
 					if p == "" {
 						if !at.Equal(*value) {
@@ -124,6 +140,9 @@ func DateTimePicker(c *ui.Context, value *time.Time, opts DateTimePickerOptions)
 		cancelled = true
 	}
 	*wasOpen = *open
+	if !*open {
+		*problem = ""
+	}
 	return DateTimeResult{Element: col, changed: changed, cancelled: cancelled}
 }
 
@@ -132,7 +151,7 @@ func dateTimeConfirm(c *ui.Context, d Date, t TimeOfDay, loc *time.Location, opt
 	if p := timePickerProblem(c, t, cfg); p != "" {
 		return time.Time{}, p
 	}
-	wall := fmt.Sprintf("%v %s", d, timeText(c, t, cfg))
+	wall := d.Format(opts.Layout) + " " + timeText(c, t, cfg)
 	at, n := dateTimeResolve(d, t, loc)
 	switch {
 	case n == 0:
@@ -142,14 +161,14 @@ func dateTimeConfirm(c *ui.Context, d Date, t TimeOfDay, loc *time.Location, opt
 		slog.Debug("mujica: date_time_picker ambiguous", "wall", wall, "zone", loc.String())
 		return at, fmt.Sprintf(msg(c, "date_time_picker.ambiguous"), wall, loc.String())
 	case !opts.Min.IsZero() && at.Before(opts.Min):
-		return at, fmt.Sprintf(msg(c, "calendar.before_min"), dateTimeText(c, opts.Min.In(loc), cfg))
+		return at, fmt.Sprintf(msg(c, "calendar.before_min"), dateTimeText(c, opts.Min.In(loc), opts.Layout, cfg))
 	case !opts.Max.IsZero() && at.After(opts.Max):
-		return at, fmt.Sprintf(msg(c, "calendar.after_max"), dateTimeText(c, opts.Max.In(loc), cfg))
+		return at, fmt.Sprintf(msg(c, "calendar.after_max"), dateTimeText(c, opts.Max.In(loc), opts.Layout, cfg))
 	}
 	return at, ""
 }
 
-// dateTimeResolve finds the instants showing wall time d t in loc: none in a DST gap, two in an overlap.
+// dateTimeResolve counts instants for a wall time: 0 gap, 2 overlap.
 func dateTimeResolve(d Date, t TimeOfDay, loc *time.Location) (time.Time, int) {
 	wall := time.Date(d.Year, d.Month, d.Day, t.Hour, t.Minute, t.Second, 0, time.UTC)
 	guess := time.Date(d.Year, d.Month, d.Day, t.Hour, t.Minute, t.Second, 0, loc)
@@ -175,7 +194,7 @@ func dateTimeResolve(d Date, t TimeOfDay, loc *time.Location) (time.Time, int) {
 	return hits[0], len(hits)
 }
 
-// dateTimeText formats a wall time with the picker's clock style.
-func dateTimeText(c *ui.Context, w time.Time, cfg timeConfig) string {
-	return DateOf(w).String() + " " + timeText(c, TimeOfDay{w.Hour(), w.Minute(), w.Second()}, cfg) + " " + w.Format("MST")
+// dateTimeText formats a wall time with the picker's date layout and clock style.
+func dateTimeText(c *ui.Context, w time.Time, layout string, cfg timeConfig) string {
+	return w.Format(layout) + " " + timeText(c, TimeOfDay{w.Hour(), w.Minute(), w.Second()}, cfg) + " " + w.Format("MST")
 }
diff --git a/datetime.go b/datetime.go
index 9da7642..e258df2 100644
--- a/datetime.go
+++ b/datetime.go
@@ -2,6 +2,7 @@ package mujica
 
 import (
 	"fmt"
+	"log/slog"
 	"time"
 
 	"github.com/egoist/mygo/ui"
@@ -11,8 +12,7 @@ import (
 	"mujicaui/theme"
 )
 
-// Date is a calendar day with no time of day and no location.
-// The zero value means no date.
+// Date is a calendar day without clock or location; zero means none.
 type Date struct {
 	Year  int
 	Month time.Month
@@ -136,28 +136,33 @@ func datetimeIconButton(c *ui.Context, icon, label string) *ui.Element {
 }
 
 // datetimeField styles row as a single-line field: solid fill and fine border.
-func datetimeField(c *ui.Context, row *ui.Element, invalid bool) *ui.Element {
+func datetimeField(c *ui.Context, row *ui.Element, invalid, readOnly bool) *ui.Element {
 	k := Tokens(c)
 	d := Density(c)
-	border := k.ControlBorder
+	bg, border := k.Surface, k.ControlBorder
 	switch {
 	case invalid:
 		border = k.Danger
+	case readOnly:
+		bg, border = k.Background, k.Border
 	case row.FocusWithin():
 		border = k.Focus
 	case row.Hovered():
 		border = k.Text
 	}
 	return row.MinHeight(d.ControlHeight()).Padding(0, d.Unit()).PaddingX(d.Unit()*3).Gap(d.Unit()).
-		AlignItems(ui.Center).Radius(theme.ControlRadius).Background(k.Surface).Border(theme.BorderWidth, border)
+		AlignItems(ui.Center).Radius(theme.ControlRadius).Background(bg).Border(theme.BorderWidth, border)
 }
 
-// datetimeTrigger is the button inside a field that shows text and opens a popup.
+// datetimeTrigger is the popup button inside a field; Cmd+C copies its text.
 func datetimeTrigger(c *ui.Context, text, placeholder, icon string) *ui.Element {
 	k := Tokens(c)
 	b := ui.ButtonBase(c).Grow(1).Shrink(1).Justify(ui.Start).Gap(Density(c).Unit() * 2).
-		MinHeight(theme.MinHitSize).Radius(theme.ControlRadius)
+		MinHeight(theme.MinHitSize).Radius(theme.ControlRadius).Role(ui.RolePopUpButton)
 	internal.Ring(b, k.Focus, theme.ControlRadius)
+	if b.Shortcut(ui.Cmd, ui.KeyC) && text != "" {
+		c.WriteClipboard(text)
+	}
 	b.Children(func() {
 		ui.Icon(c, icons.Must(icon)).Size(16, 16).TextColor(k.TextMuted)
 		if text == "" {
@@ -169,10 +174,14 @@ func datetimeTrigger(c *ui.Context, text, placeholder, icon string) *ui.Element
 	return b
 }
 
-// datetimePopup shows fn in a popup panel below anchor while *open is set.
-func datetimePopup(c *ui.Context, anchor *ui.Element, open *bool, fn func()) *ui.Element {
+// datetimePopup shows fn below anchor while *open; a disabled or read-only anchor closes it.
+func datetimePopup(c *ui.Context, anchor *ui.Element, open *bool, readOnly bool, fn func()) *ui.Element {
 	k := Tokens(c)
 	d := Density(c)
+	if *open && (readOnly || anchor.IsDisabled()) {
+		slog.Debug("mujica: datetime popup closed by state", "readOnly", readOnly)
+		*open = false
+	}
 	return ui.PopoverBase(c, anchor, open, func(panel *ui.Element) {
 		born := ui.Local(panel, "datetime-born", func() bool { return true })
 		if *born {
@@ -192,7 +201,7 @@ func datetimeError(c *ui.Context, text string) {
 	if text == "" {
 		return
 	}
-	ui.Text(c, text).FontSize(theme.CaptionSize).TextColor(Tokens(c).Danger).Role(ui.RoleStatus)
+	ui.Text(c, text).FontSize(FontSize(c, theme.CaptionSize)).TextColor(Tokens(c).Danger).Role(ui.RoleStatus)
 }
 
 // datetimeFooter lays out popup actions at the end of a row.
diff --git a/datetime_grid.go b/datetime_grid.go
index 7cb7c48..7c35d05 100644
--- a/datetime_grid.go
+++ b/datetime_grid.go
@@ -39,7 +39,7 @@ func datetimeGrid(c *ui.Context, cursor *int, cfg datetimeGridConfig) (picked in
 			if datetimeIconButton(c, "chevron-left", cfg.prev).Clicked() {
 				*cursor, *keyed = *cursor-cfg.page, false
 			}
-			ui.Text(c, cfg.title(start)).Font(theme.SerifFont).FontSize(theme.BodySize + 2).Bold().
+			ui.Text(c, cfg.title(start)).Font(theme.SerifFont).FontSize(FontSize(c, theme.BodySize+2)).Bold().
 				TextColor(k.Text).Grow(1).TextAlign(ui.Center).SingleLine()
 			if datetimeIconButton(c, "chevron-right", cfg.next).Clicked() {
 				*cursor, *keyed = *cursor+cfg.page, false
@@ -61,10 +61,9 @@ func datetimeGrid(c *ui.Context, cursor *int, cfg datetimeGridConfig) (picked in
 		case cells.Shortcut(0, ui.KeyPageDown):
 			*cursor += cfg.page
 		case cells.Shortcut(0, ui.KeyHome):
-			*cursor, _ = cfg.pageOf(*cursor)
+			*cursor, _ = datetimeGridBounds(*cursor, cfg)
 		case cells.Shortcut(0, ui.KeyEnd):
-			s, n := cfg.pageOf(*cursor)
-			*cursor = s + n - 1
+			_, *cursor = datetimeGridBounds(*cursor, cfg)
 		default:
 			moved = false
 		}
@@ -145,33 +144,46 @@ func datetimeGridCell(c *ui.Context, o, start, cursor int, cfg datetimeGridConfi
 	return cell.Clicked() && enabled
 }
 
+// datetimeGridBounds returns the page's own first and last ordinals.
+func datetimeGridBounds(o int, cfg datetimeGridConfig) (first, last int) {
+	start, n := cfg.pageOf(o)
+	first, last = start, start+n-1
+	for first < last && cfg.muted(first, start) {
+		first++
+	}
+	for last > first && cfg.muted(last, start) {
+		last--
+	}
+	return first, last
+}
+
 // datetimeGridField is the field and popup shared by MonthPicker and YearPicker.
 type datetimeGridField struct {
 	text, placeholder, label string
 	clearable, hasValue      bool
-	disabled                 bool
+	disabled, readOnly       bool
 	// home is the ordinal the popup opens on.
 	home int
 }
 
-// datetimeGridPicker draws f and its popup grid; it returns the column, a picked ordinal and whether Clear was pressed.
+// datetimeGridPicker draws f and its popup; reports a pick or clear.
 func datetimeGridPicker(c *ui.Context, f datetimeGridField, cfg datetimeGridConfig) (col *ui.Element, picked int, ok, cleared bool) {
 	d := Density(c)
 	col = ui.Column(c).Width(d.ControlHeight() * 6).Gap(d.Unit()).AlignItems(ui.Stretch).Disabled(f.disabled)
 	open := ui.Local(col, "datetime-grid-open", func() bool { return false })
 	cursor := ui.Local(col, "datetime-grid-cursor", func() int { return 0 })
 	col.Children(func() {
-		field := datetimeField(c, ui.Row(c), false)
+		field := datetimeField(c, ui.Row(c), false, f.readOnly)
 		field.Children(func() {
 			t := datetimeTrigger(c, f.text, f.placeholder, "calendar").Label(f.label).Description(f.text)
-			if t.Clicked() || !*open && t.Shortcut(0, ui.KeyDown) {
+			if !f.readOnly && (t.Clicked() || !*open && t.Shortcut(0, ui.KeyDown)) {
 				*open, *cursor = !*open, f.home
 			}
-			if f.clearable && f.hasValue && datetimeIconButton(c, "x", msg(c, "calendar.clear")).Clicked() {
+			if f.clearable && f.hasValue && !f.readOnly && datetimeIconButton(c, "x", msg(c, "calendar.clear")).Clicked() {
 				cleared = true
 			}
 		})
-		datetimePopup(c, field, open, func() {
+		datetimePopup(c, field, open, f.readOnly, func() {
 			cfg.autoFocus = true
 			if picked, ok = datetimeGrid(c, cursor, cfg); ok {
 				*open = false
diff --git a/datetime_review_test.go b/datetime_review_test.go
new file mode 100644
index 0000000..a995fbf
--- /dev/null
+++ b/datetime_review_test.go
@@ -0,0 +1,236 @@
+package mujica
+
+import (
+	"image/color"
+	"testing"
+	"time"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/theme"
+)
+
+// datePickerLive builds a DatePicker whose options a test changes between frames.
+func datePickerLive(value *Date, opts *DatePickerOptions, changes *int) *ui.Tester {
+	return ui.NewTester(func(c *ui.Context) {
+		Use(c, Settings{Mode: Light})
+		ui.Column(c).Padding(16).Gap(8).Children(func() {
+			o := *opts
+			o.Today, o.Label = calendarToday, "Due"
+			if DatePicker(c, value, o).Changed() {
+				*changes++
+			}
+		})
+	}, 420, 460)
+}
+
+func TestDatePickerDisablingClosesPopup(t *testing.T) {
+	v, n := Date{2026, time.October, 5}, 0
+	opts := DatePickerOptions{}
+	tt := datePickerLive(&v, &opts, &n)
+	_ = tt.Click("Open calendar")
+	day := datetimeTestLabel(oct(5))
+	if !tt.Focused(day) {
+		t.Fatal("setup: the popup should focus the chosen day")
+	}
+	opts.Disabled = true
+	tt.Frame()
+	tt.Key(0, ui.KeyRight)
+	tt.Key(0, ui.KeyEnter)
+	_ = tt.Click(datetimeTestLabel(oct(20)))
+	if v != oct(5) || n != 0 {
+		t.Fatalf("disabled picker committed %v (%d events)", v, n)
+	}
+	if tt.HasText("October 2026") || tt.Focused(datetimeTestLabel(oct(6))) || tt.Focused("Due") {
+		t.Fatal("the popup should close and nothing in the disabled picker keep focus")
+	}
+}
+
+func TestDatePickerDisabledBlocksInput(t *testing.T) {
+	v, n := Date{2026, time.October, 5}, 0
+	tt := datePickerTester(&v, DatePickerOptions{Label: "Due", Disabled: true}, &n)
+	_ = tt.Click("Due")
+	tt.Type("2027-01-01")
+	tt.Key(0, ui.KeyEnter)
+	tt.Key(0, ui.KeyDown)
+	_ = tt.Click("Open calendar")
+	if v != oct(5) || n != 0 || tt.Focused("Due") || tt.HasText("October 2026") {
+		t.Fatalf("disabled picker took input: %v (%d)", v, n)
+	}
+}
+
+func TestTimePickerKeepsInvalidHour(t *testing.T) {
+	v, n := TimeOfDay{9, 30, 0}, 0
+	tt := timePickerTester(&v, TimePickerOptions{}, &n)
+	_ = tt.Click("Alarm: Hours")
+	tt.Key(0, ui.Key2)
+	tt.Key(0, ui.Key9)
+	if v != (TimeOfDay{2, 30, 0}) || n != 1 {
+		t.Fatalf("first digit should apply: %v", v)
+	}
+	if !tt.HasText("29") || !tt.HasText("Hours must be from 0 to 23.") || !tt.Focused("Alarm: Hours") {
+		t.Fatalf("29 should stay shown with an error: %v", tt.Texts())
+	}
+	tt.Key(0, ui.Key1)
+	tt.Key(0, ui.Key5)
+	if v != (TimeOfDay{15, 30, 0}) || n != 3 || tt.HasText("Hours must be") {
+		t.Fatalf("fixing the hour: %v", v)
+	}
+}
+
+func TestTimeSegmentDescription(t *testing.T) {
+	var got []string
+	ui.NewTester(func(c *ui.Context) {
+		Use(c, Settings{})
+		got = []string{timeSegmentDescription(c, timeHourPart, " 9", 1, 12), timeSegmentDescription(c, timePeriodPart, "PM", 0, 59)}
+	}, 100, 100)
+	if got[0] != "9, from 1 to 12" || got[1] != "PM" {
+		t.Fatalf("descriptions %q", got)
+	}
+}
+
+func TestTimePickerSegmentFocusRing(t *testing.T) {
+	v := TimeOfDay{9, 30, 0}
+	tt := timePickerTester(&v, TimePickerOptions{}, new(int))
+	tt.SetPreferences(ui.Preferences{ReduceMotion: true, TextScale: 1})
+	tt.Key(0, ui.KeyTab)
+	r, ok := tt.Find("Alarm: Hours")
+	if !ok || !tt.Focused("Alarm: Hours") {
+		t.Fatal("setup: hours not focused")
+	}
+	want := theme.Light().Focus
+	img := tt.Image()
+	found := false
+	for dy := float32(-4); dy <= -2 && !found; dy++ {
+		c := img.RGBAAt(int(r.X+r.W/2), int(r.Y+dy))
+		found = datetimeNear(c, want)
+	}
+	if !found {
+		t.Fatal("no focus ring above the focused segment")
+	}
+}
+
+func datetimeNear(c color.RGBA, w ui.Color) bool {
+	d := func(a, b uint8) int {
+		if a > b {
+			return int(a - b)
+		}
+		return int(b - a)
+	}
+	return d(c.R, w.R)+d(c.G, w.G)+d(c.B, w.B) < 60
+}
+
+func TestDatePickerLayoutChangeReformats(t *testing.T) {
+	v, n := Date{2026, time.October, 5}, 0
+	opts := DatePickerOptions{}
+	tt := datePickerLive(&v, &opts, &n)
+	opts.Layout = "02/01/2006"
+	tt.Frame()
+	_ = tt.Click("Due")
+	tt.Key(0, ui.KeyEnter)
+	if v != oct(5) || n != 0 || tt.HasText("Enter a date like") {
+		t.Fatalf("committed text kept the old layout: %v", tt.Texts())
+	}
+	_ = tt.Click("Due")
+	tt.Command("selectAll")
+	tt.Type("12/10")
+	opts.Layout = "2006-01-02"
+	tt.Frame()
+	tt.Key(0, ui.KeyEnter)
+	if !tt.HasText("Enter a date like 2026-10-05.") || v != oct(5) {
+		t.Fatal("a draft being edited should be kept across a layout change")
+	}
+}
+
+func TestYearPickerHomeEndStayOnPage(t *testing.T) {
+	v := 2026
+	tt := yearPickerTester(&v, YearPickerOptions{}, new(int))
+	tt.Key(0, ui.KeyTab)
+	tt.Key(0, ui.KeyDown)
+	tt.Key(0, ui.KeyHome)
+	if !tt.HasText("2020 – 2029") || !tt.Focused("2020") {
+		t.Fatalf("Home left the page: %v", tt.Texts()[:4])
+	}
+	tt.Key(0, ui.KeyEnd)
+	if !tt.HasText("2020 – 2029") || !tt.Focused("2029") {
+		t.Fatal("End left the page")
+	}
+}
+
+func TestDatePickerReadOnly(t *testing.T) {
+	v, n := Date{2026, time.October, 5}, 0
+	tt := datePickerTester(&v, DatePickerOptions{Label: "Due", ReadOnly: true, Clearable: true}, &n)
+	_ = tt.Click("Due")
+	if !tt.Focused("Due") {
+		t.Fatal("read-only field should take focus")
+	}
+	tt.Command("selectAll")
+	tt.Command("copy")
+	if tt.Clipboard() != "2026-10-05" {
+		t.Fatalf("copied %q", tt.Clipboard())
+	}
+	tt.Type("2027-01-01")
+	tt.Key(0, ui.KeyEnter)
+	tt.Key(0, ui.KeyDown)
+	if v != oct(5) || n != 0 || tt.HasText("October 2026") || tt.HasText("Open calendar") || tt.HasText("Clear") {
+		t.Fatalf("read-only picker changed: %v %v", v, tt.Texts())
+	}
+	tt.Key(0, ui.KeyTab)
+	tt.Key(ui.Shift, ui.KeyTab)
+	tt.Command("selectAll")
+	tt.Command("copy")
+	if tt.Clipboard() != "2026-10-05" {
+		t.Fatalf("typed text leaked into the field: %q", tt.Clipboard())
+	}
+}
+
+func TestTimePickerReadOnly(t *testing.T) {
+	v, n := TimeOfDay{9, 30, 0}, 0
+	tt := timePickerTester(&v, TimePickerOptions{ReadOnly: true}, &n)
+	tt.Key(0, ui.KeyTab)
+	tt.Key(0, ui.KeyUp)
+	tt.Key(0, ui.Key1)
+	tt.Key(ui.Alt, ui.KeyDown)
+	if !tt.Focused("Alarm: Hours") || v != (TimeOfDay{9, 30, 0}) || n != 0 || tt.HasText("Choose time") {
+		t.Fatalf("read-only time changed: %v", v)
+	}
+	tt.Key(ui.Cmd, ui.KeyC)
+	if tt.Clipboard() != "09:30" {
+		t.Fatalf("copied %q", tt.Clipboard())
+	}
+}
+
+func TestMonthPickerReadOnly(t *testing.T) {
+	v, n := YearMonth{2026, time.May}, 0
+	tt := monthPickerTester(&v, MonthPickerOptions{ReadOnly: true, Clearable: true}, &n)
+	_ = tt.Click("Billing month")
+	tt.Key(0, ui.KeyDown)
+	if tt.HasText("January") || tt.HasText("Clear") || !tt.Focused("Billing month") {
+		t.Fatalf("read-only month opened: %v", tt.Texts())
+	}
+	tt.Key(ui.Cmd, ui.KeyC)
+	if tt.Clipboard() != "May 2026" || v != (YearMonth{2026, time.May}) || n != 0 {
+		t.Fatalf("copied %q, value %v", tt.Clipboard(), v)
+	}
+}
+
+func TestDateTimePickerLayout(t *testing.T) {
+	v := time.Time{}
+	n, x := 0, 0
+	maxT := time.Date(2026, time.October, 10, 12, 0, 0, 0, time.UTC)
+	tt := dateTimeTester(t, &v, DateTimePickerOptions{Location: time.UTC, Max: maxT, Layout: "02/01/2006"}, &n, &x)
+	_ = tt.Click("Meeting")
+	_ = tt.Click(datetimeTestLabel(oct(10)))
+	_ = tt.Click("Time: Hours")
+	tt.Key(0, ui.Key1)
+	tt.Key(0, ui.Key3)
+	_ = tt.Click("Confirm")
+	if n != 0 || !tt.HasText("Choose 10/10/2026 12:00 UTC or earlier.") {
+		t.Fatalf("error ignores the layout: %v", tt.Texts())
+	}
+	_ = tt.Click(datetimeTestLabel(oct(9)))
+	_ = tt.Click("Confirm")
+	if n != 1 || !tt.HasText("09/10/2026 13:00 UTC") {
+		t.Fatalf("display ignores the layout: %v", tt.Texts())
+	}
+}
diff --git a/docs/components/051-calendar.md b/docs/components/051-calendar.md
index 72d7a72..c891a73 100644
--- a/docs/components/051-calendar.md
+++ b/docs/components/051-calendar.md
@@ -53,3 +53,4 @@ ui.Render(view, 400, 300, 1)
 - MyGo 的 `ui.Calendar` 固定周一起始、只有英文且不支持禁用日期（ui/date.go:85-160），因此本组件基于 `RadioBase` 自绘网格，不复用 `ui.Calendar`。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/docs/components/052-date-picker.md b/docs/components/052-date-picker.md
index 4a7b7a4..0a3352c 100644
--- a/docs/components/052-date-picker.md
+++ b/docs/components/052-date-picker.md
@@ -33,12 +33,13 @@ ui.Render(view, 400, 300, 1)
 | `Today` | `Date` | 零值（系统时钟） | 弹层日历中的今日标记；空值时弹层打开到此月份。 |
 | `Clearable` | `bool` | false | 显示清空按钮；清空输入后提交表示“无日期”。 |
 | `Placeholder` | `string` | 内置“选择日期” | 空输入框的占位文字。 |
+| `ReadOnly` | `bool` | false | 只读：可聚焦、可复制（Cmd/Ctrl+C），不能修改，不打开弹层。 |
 | `Disabled` | `bool` | false | 禁用输入与弹层。 |
 | `Label` | `string` | 占位文字 | 辅助技术名称。 |
 
 ## 状态
 
-默认、悬停（边框加深）、聚焦（焦点色边框）、错误（危险色边框 + 下方说明，输入保留）、禁用。弹层内日历状态同 Calendar。
+默认、悬停（边框加深）、聚焦（焦点色边框）、只读（背景与边框减弱，可选择复制）、错误（危险色边框 + 下方说明，输入保留）、禁用。弹层内日历状态同 Calendar。
 
 ## 事件
 
@@ -54,6 +55,7 @@ ui.Render(view, 400, 300, 1)
 
 - 无效或越界的输入（如 2026-02-30）显示具体错误并保留原文，不会被修正为相邻日期。
 - MyGo 的 `ui.DateInput` 固定格式且不可键入（ui/date.go:13），因此本组件组合 `TextInputBase` 与自绘日历弹层（`PopoverBase`）。
-- 暂不提供只读模式：MyGo v0.2.10 未公开 TextInputBase 的只读开关。
+- 只读模式沿用 TextInput 的做法：编辑副本并在每帧恢复，文本仍可选择与复制。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/docs/components/053-date-range-picker.md b/docs/components/053-date-range-picker.md
index f400753..9a50075 100644
--- a/docs/components/053-date-range-picker.md
+++ b/docs/components/053-date-range-picker.md
@@ -30,6 +30,7 @@ ui.Render(view, 400, 300, 1)
 | `DisableDate` | `func(Date) bool` | nil | 不可选日期；范围内包含此类日期时拒绝并提示。 |
 | `WeekStart` | `WeekStart` | `WeekStartLocale` | 周起始日。 |
 | `Today` | `Date` | 零值（系统时钟） | 今日标记与空值时的起始月份。 |
+| `ReadOnly` | `bool` | false | 只读：可聚焦、可复制（Cmd/Ctrl+C），不能修改，不打开弹层。 |
 | `Disabled` | `bool` | false | 禁用。 |
 | `Label` | `string` | 内置“日期范围” | 辅助技术名称。 |
 
@@ -55,3 +56,4 @@ ui.Render(view, 400, 300, 1)
 - `DateRange` 为闭区间，`Days()` 计入两端。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/docs/components/054-time-picker.md b/docs/components/054-time-picker.md
index 3740297..0014447 100644
--- a/docs/components/054-time-picker.md
+++ b/docs/components/054-time-picker.md
@@ -30,12 +30,13 @@ ui.Render(view, 400, 300, 1)
 | `SecondStep` | `int` | 0（即 1） | 秒步长，必须整除 60。 |
 | `Min` | `TimeOfDay` | 00:00:00 | 最早时间。 |
 | `Max` | `TimeOfDay` | 零值（即 23:59:59） | 最晚时间。 |
+| `ReadOnly` | `bool` | false | 只读：可聚焦、可复制（Cmd/Ctrl+C），不能修改，不打开弹层。 |
 | `Disabled` | `bool` | false | 禁用。 |
 | `Label` | `string` | 空 | 组名；各段名称为“Label: 时/分/秒”。 |
 
 ## 状态
 
-默认、悬停、聚焦段（酒红填充）、错误（危险色边框 + 说明，草稿保留）、禁用。弹层列表中超出范围的项禁用。
+默认、悬停、聚焦段（酒红填充 + 键盘焦点环）、只读、错误（危险色边框 + 说明，草稿保留）、禁用。弹层列表中超出范围的项禁用。
 
 ## 事件
 
@@ -52,8 +53,9 @@ ui.Render(view, 400, 300, 1)
 
 ## 限制
 
-- 超出范围或不符合步长的时间会提示，不会被自动夹取或取整。
+- 超出范围或不符合步长的时间会提示，不会被自动夹取或取整；键入超出段范围的数字（如小时 29）会保留显示并报错。
 - 段顺序固定为“时:分:秒 上午/下午”，zh-CN 下上午/下午也位于末尾。
 - MyGo 的 `ui.TimeInput` 只有时分且无 12 小时制、步长和范围（ui/timeinput.go:18），因此本组件自绘分段。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/docs/components/055-time-range-picker.md b/docs/components/055-time-range-picker.md
index 377fe2e..4aac9bf 100644
--- a/docs/components/055-time-range-picker.md
+++ b/docs/components/055-time-range-picker.md
@@ -31,6 +31,7 @@ ui.Render(view, 400, 300, 1)
 | `Min` | `TimeOfDay` | 00:00:00 | 两端最早时间。 |
 | `Max` | `TimeOfDay` | 零值（即 23:59:59） | 两端最晚时间。 |
 | `AllowOvernight` | `bool` | false | 允许结束早于开始，表示次日结束，并显示“次日”。 |
+| `ReadOnly` | `bool` | false | 只读：可聚焦、可复制（Cmd/Ctrl+C），不能修改，不打开弹层。 |
 | `Disabled` | `bool` | false | 禁用。 |
 | `Label` | `string` | 空 | 整组名称。 |
 
@@ -53,3 +54,4 @@ ui.Render(view, 400, 300, 1)
 - `TimeRange.Overnight()` 报告是否跨午夜。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/docs/components/056-date-time-picker.md b/docs/components/056-date-time-picker.md
index b6dcb14..d2a7efa 100644
--- a/docs/components/056-date-time-picker.md
+++ b/docs/components/056-date-time-picker.md
@@ -29,6 +29,7 @@ ui.Render(view, 400, 300, 1)
 | 字段 | 类型 | 默认值 | 含义 |
 | --- | --- | --- | --- |
 | `Location` | `*time.Location` | 必填 | 用户编辑所用时区；为 nil 时 panic。 |
+| `Layout` | `string` | `2006-01-02` | 日期部分的 Go 时间布局，用于显示与错误说明。 |
 | `Min` | `time.Time` | 零值 | 最早时刻。 |
 | `Max` | `time.Time` | 零值 | 最晚时刻。 |
 | `Seconds` | `bool` | false | 显示秒。 |
@@ -36,6 +37,7 @@ ui.Render(view, 400, 300, 1)
 | `MinuteStep` | `int` | 0（即 1） | 分钟步长。 |
 | `WeekStart` | `WeekStart` | `WeekStartLocale` | 周起始日。 |
 | `Today` | `Date` | 零值（系统时钟） | 今日标记与空值时的默认日期。 |
+| `ReadOnly` | `bool` | false | 只读：可聚焦、可复制（Cmd/Ctrl+C），不能修改，不打开弹层。 |
 | `Disabled` | `bool` | false | 禁用。 |
 | `Label` | `string` | 内置占位文字 | 辅助技术名称。 |
 
@@ -60,3 +62,4 @@ ui.Render(view, 400, 300, 1)
 - 空值（零 `time.Time`）打开时默认今天 00:00。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/docs/components/057-month-picker.md b/docs/components/057-month-picker.md
index c0eb9e5..1a701c1 100644
--- a/docs/components/057-month-picker.md
+++ b/docs/components/057-month-picker.md
@@ -29,6 +29,7 @@ ui.Render(view, 400, 300, 1)
 | `DisableMonth` | `func(YearMonth) bool` | nil | 不可选月份。 |
 | `Clearable` | `bool` | false | 有值时显示清空按钮。 |
 | `Today` | `Date` | 零值（系统时钟） | 标记当前月份。 |
+| `ReadOnly` | `bool` | false | 只读：可聚焦、可复制（Cmd/Ctrl+C），不能修改，不打开弹层。 |
 | `Disabled` | `bool` | false | 禁用。 |
 | `Label` | `string` | 内置“选择月份” | 辅助技术名称。 |
 
@@ -53,3 +54,4 @@ ui.Render(view, 400, 300, 1)
 - 键盘移到不可选月份时焦点保持在原处，可继续移动。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/docs/components/058-year-picker.md b/docs/components/058-year-picker.md
index 2ff6c6f..2b10e5a 100644
--- a/docs/components/058-year-picker.md
+++ b/docs/components/058-year-picker.md
@@ -29,6 +29,7 @@ ui.Render(view, 400, 300, 1)
 | `DisableYear` | `func(int) bool` | nil | 不可选年份。 |
 | `Clearable` | `bool` | false | 有值时显示清空按钮。 |
 | `Today` | `Date` | 零值（系统时钟） | 标记当前年份。 |
+| `ReadOnly` | `bool` | false | 只读：可聚焦、可复制（Cmd/Ctrl+C），不能修改，不打开弹层。 |
 | `Disabled` | `bool` | false | 禁用。 |
 | `Label` | `string` | 内置“选择年份” | 辅助技术名称。 |
 
@@ -53,3 +54,4 @@ ui.Render(view, 400, 300, 1)
 - 只支持公元 1 年及以后；值为负数时 panic。
 - 日期与时间值不带时区：`Date`、`YearMonth`、`TimeOfDay` 只保存日历字段，组件内部计算不做 UTC 转换。
 - `Today` 为零值时读取 `c.Now()`（系统本地时区）；需要固定“今天”（测试、跨时区应用）时显式传入。
+- 无障碍：MyGo v0.2.10 没有公开设置弹出按钮展开状态（`expanded`）、数值范围（`hasRange`/`accRange`）与值（`accValue`）的接口，这些字段只在 MyGo 内部组件中赋值（ui/element.go:286-295，例如 ui/base.go:297、ui/indicators.go:61）。因此触发器只能声明为 `RolePopUpButton` 而无法报告展开状态；时间段以 `Description` 读出当前值与范围，错误通过 `Error()` 关联。
diff --git a/examples/gallery/pages_datetime.go b/examples/gallery/pages_datetime.go
index 07f6b8c..f547335 100644
--- a/examples/gallery/pages_datetime.go
+++ b/examples/gallery/pages_datetime.go
@@ -35,7 +35,7 @@ var datetimePages = []page{
 func dtSection(c *ui.Context, title string, fn func()) {
 	k := mujica.Tokens(c)
 	ui.Column(c).Gap(8).Children(func() {
-		ui.Text(c, title).Font(theme.SerifFont).FontSize(theme.H3Size).TextColor(k.Text)
+		ui.Text(c, title).Font(theme.SerifFont).FontSize(mujica.FontSize(c, theme.H3Size)).TextColor(k.Text)
 		fn()
 	})
 }
@@ -46,7 +46,7 @@ func dtStates(c *ui.Context, fn func(state func(name string, body func()))) {
 	ui.Row(c).Gap(24).Wrap().AlignItems(ui.Start).Children(func() {
 		fn(func(name string, body func()) {
 			ui.Column(c).Gap(6).AlignItems(ui.Start).Children(func() {
-				ui.Text(c, name).FontSize(theme.CaptionSize).TextColor(k.TextMuted)
+				ui.Text(c, name).FontSize(mujica.FontSize(c, theme.CaptionSize)).TextColor(k.TextMuted)
 				body()
 			})
 		})
@@ -128,6 +128,9 @@ func dtDatePickerDemo(c *ui.Context, log func(string)) {
 					log("DatePicker (bounded) changed: " + s.b.String())
 				}
 			})
+			state("Read-only", func() {
+				mujica.DatePicker(c, &s.d, mujica.DatePickerOptions{Label: "Signed on", Layout: layout, ReadOnly: true})
+			})
 			state("Disabled", func() {
 				mujica.DatePicker(c, &s.d, mujica.DatePickerOptions{Label: "Locked", Layout: layout, Disabled: true})
 			})
@@ -202,6 +205,11 @@ func dtTimePickerDemo(c *ui.Context, log func(string)) {
 					log("TimePicker (bounded) changed: " + s.b.String())
 				}
 			})
+			state("Read-only", func() {
+				o := base
+				o.Label, o.ReadOnly = "Logged at", true
+				mujica.TimePicker(c, &s.a, o)
+			})
 			state("Disabled", func() {
 				o := base
 				o.Label, o.Disabled = "Locked", true
@@ -261,7 +269,7 @@ func dtDateTimeDemo(c *ui.Context, log func(string)) {
 		}
 		k := mujica.Tokens(c)
 		ui.Text(c, "Try 2026-03-08 02:30 in America/New_York: the picker reports the DST gap.").
-			FontSize(theme.CaptionSize).TextColor(k.TextMuted)
+			FontSize(mujica.FontSize(c, theme.CaptionSize)).TextColor(k.TextMuted)
 	})
 }
 
@@ -288,6 +296,9 @@ func dtMonthDemo(c *ui.Context, log func(string)) {
 					log("MonthPicker changed: " + s.v.String())
 				}
 			})
+			state("Read-only", func() {
+				mujica.MonthPicker(c, &s.v, mujica.MonthPickerOptions{Label: "Closed month", ReadOnly: true})
+			})
 			state("Disabled", func() {
 				mujica.MonthPicker(c, &s.v, mujica.MonthPickerOptions{Label: "Locked", Disabled: true})
 			})
@@ -311,6 +322,9 @@ func dtYearDemo(c *ui.Context, log func(string)) {
 					log(fmt.Sprintf("YearPicker changed: %d", s.v))
 				}
 			})
+			state("Read-only", func() {
+				mujica.YearPicker(c, &s.v, mujica.YearPickerOptions{Label: "Founded", ReadOnly: true})
+			})
 			state("Disabled", func() {
 				mujica.YearPicker(c, &s.v, mujica.YearPickerOptions{Label: "Locked", Disabled: true})
 			})
diff --git a/messages_datetime.go b/messages_datetime.go
index 1d44b95..2b4dd2d 100644
--- a/messages_datetime.go
+++ b/messages_datetime.go
@@ -63,6 +63,8 @@ func init() {
 		"time_picker.open":         {"Choose time", "选择时间"},
 		"time_picker.minute_step":  {"Minutes must be a multiple of %d.", "分钟须为 %d 的倍数。"},
 		"time_picker.second_step":  {"Seconds must be a multiple of %d.", "秒须为 %d 的倍数。"},
+		"time_picker.segment":      {"%[1]s, from %[2]d to %[3]d", "%[1]s，范围 %[2]d–%[3]d"},
+		"time_picker.part_range":   {"%[1]s must be from %[2]d to %[3]d.", "%[1]s须在 %[2]d 至 %[3]d 之间。"},
 		"time_picker.out_of_range": {"Choose a time from %s to %s.", "请选择 %s 至 %s 之间的时间。"},
 
 		"time_range_picker.start":    {"Start time", "开始时间"},
diff --git a/month_picker.go b/month_picker.go
index b88359a..766686d 100644
--- a/month_picker.go
+++ b/month_picker.go
@@ -44,11 +44,13 @@ type MonthPickerOptions struct {
 	// Today marks the current month; zero uses the system clock.
 	Today    Date
 	Disabled bool
+	// ReadOnly keeps the field focusable and copyable but blocks the popup and clearing.
+	ReadOnly bool
 	// Label names the field for assistive technology.
 	Label string
 }
 
-// MonthPicker chooses a month into *value from a year page; PageUp and PageDown change the year.
+// MonthPicker chooses a month into *value from a year page.
 func MonthPicker(c *ui.Context, value *YearMonth, opts MonthPickerOptions) DateTimeResult {
 	for _, m := range []YearMonth{*value, opts.Min, opts.Max} {
 		if !m.IsZero() && (m.Month < time.January || m.Month > time.December) {
@@ -75,7 +77,7 @@ func MonthPicker(c *ui.Context, value *YearMonth, opts MonthPickerOptions) DateT
 	}
 	col, picked, ok, cleared := datetimeGridPicker(c, datetimeGridField{
 		text: text, placeholder: msg(c, "month_picker.placeholder"), label: label,
-		clearable: opts.Clearable, hasValue: !value.IsZero(), disabled: opts.Disabled, home: home.ordinal(),
+		clearable: opts.Clearable, hasValue: !value.IsZero(), disabled: opts.Disabled, readOnly: opts.ReadOnly, home: home.ordinal(),
 	}, datetimeGridConfig{
 		pageOf:  func(o int) (int, int) { return yearMonthOf(o).Year * 12, 12 },
 		cols:    3,
diff --git a/testdata/snapshots/darwin/time_picker-dark.png b/testdata/snapshots/darwin/time_picker-dark.png
index 12a4377..2486b12 100644
Binary files a/testdata/snapshots/darwin/time_picker-dark.png and b/testdata/snapshots/darwin/time_picker-dark.png differ
diff --git a/testdata/snapshots/darwin/time_picker-light.png b/testdata/snapshots/darwin/time_picker-light.png
index de6c31a..9f6887f 100644
Binary files a/testdata/snapshots/darwin/time_picker-light.png and b/testdata/snapshots/darwin/time_picker-light.png differ
diff --git a/testdata/snapshots/darwin/time_range_picker-dark.png b/testdata/snapshots/darwin/time_range_picker-dark.png
index d3f8038..ea34102 100644
Binary files a/testdata/snapshots/darwin/time_range_picker-dark.png and b/testdata/snapshots/darwin/time_range_picker-dark.png differ
diff --git a/testdata/snapshots/darwin/time_range_picker-light.png b/testdata/snapshots/darwin/time_range_picker-light.png
index e32d8f1..bb5b65b 100644
Binary files a/testdata/snapshots/darwin/time_range_picker-light.png and b/testdata/snapshots/darwin/time_range_picker-light.png differ
diff --git a/time_picker.go b/time_picker.go
index 12a4391..57f4eac 100644
--- a/time_picker.go
+++ b/time_picker.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log/slog"
 	"strconv"
+	"strings"
 
 	"github.com/egoist/mygo/ui"
 
@@ -49,12 +50,13 @@ type TimePickerOptions struct {
 	// Min and Max bound the time; a zero Max means 23:59:59.
 	Min, Max TimeOfDay
 	Disabled bool
+	// ReadOnly keeps the segments focusable and copyable but blocks edits and the popup.
+	ReadOnly bool
 	// Label names the field for assistive technology.
 	Label string
 }
 
-// TimePicker edits *value by typing into hour, minute and second segments or by choosing in a popup.
-// Times outside the range or off the step are reported and not written.
+// TimePicker edits *value in segments or a popup.
 func TimePicker(c *ui.Context, value *TimeOfDay, opts TimePickerOptions) DateTimeResult {
 	cfg := timePickerConfig("TimePicker", opts)
 	if !value.Valid() {
@@ -65,17 +67,23 @@ func TimePicker(c *ui.Context, value *TimeOfDay, opts TimePickerOptions) DateTim
 	seen := ui.Local(col, "time-picker-seen", func() TimeOfDay { return *value })
 	problem := ui.Local(col, "time-picker-error", func() string { return "" })
 	if *seen != *value {
-		*draft, *seen, *problem = *value, *value, ""
+		*draft, *seen = *value, *value
 	}
 	changed := false
 	col.Children(func() {
-		cfg.invalid = *problem != ""
-		if _, edited := timeEditor(c, draft, cfg); edited {
-			*problem = timePickerProblem(c, *draft, cfg)
-			if *problem == "" && *draft != *value {
-				slog.Debug("mujica: time_picker change", "from", *value, "to", *draft)
-				*value, *seen, changed = *draft, *draft, true
-			}
+		cfg.problem = *problem
+		_, edited, bad := timeEditor(c, draft, cfg)
+		p := bad
+		if p == "" {
+			p = timePickerProblem(c, *draft, cfg)
+		}
+		if p != *problem {
+			*problem = p
+			c.Invalidate()
+		}
+		if edited && p == "" && *draft != *value {
+			slog.Debug("mujica: time_picker change", "from", *value, "to", *draft)
+			*value, *seen, changed = *draft, *draft, true
 		}
 		datetimeError(c, *problem)
 	})
@@ -88,13 +96,15 @@ type timeConfig struct {
 	minuteStep, secondStep int
 	min, max               TimeOfDay
 	label                  string
-	invalid                bool
+	// problem is the error shown last frame, attached to the segments.
+	problem  string
+	readOnly bool
 }
 
 // timePickerConfig checks opts and fills in defaults.
 func timePickerConfig(name string, opts TimePickerOptions) timeConfig {
 	cfg := timeConfig{seconds: opts.Seconds, hour12: opts.Hour12, minuteStep: max(opts.MinuteStep, 1),
-		secondStep: max(opts.SecondStep, 1), min: opts.Min, max: opts.Max, label: opts.Label}
+		secondStep: max(opts.SecondStep, 1), min: opts.Min, max: opts.Max, label: opts.Label, readOnly: opts.ReadOnly}
 	for _, s := range []int{opts.MinuteStep, opts.SecondStep} {
 		if s < 0 || s > 0 && 60%s != 0 {
 			panic(fmt.Sprintf("mujica: %s step %d does not divide 60", name, s))
@@ -174,15 +184,18 @@ func timeParts(cfg timeConfig) []timePart {
 	return parts
 }
 
-// timeEditor draws a segmented time field with a popup and reports whether the user edited *draft.
-func timeEditor(c *ui.Context, draft *TimeOfDay, cfg timeConfig) (field *ui.Element, edited bool) {
+// timeEditor draws segments and popup; reports edits and invalid entry.
+func timeEditor(c *ui.Context, draft *TimeOfDay, cfg timeConfig) (field *ui.Element, edited bool, bad string) {
 	k := Tokens(c)
 	d := Density(c)
-	field = datetimeField(c, ui.Row(c), cfg.invalid).Gap(d.Unit() * 2)
+	field = datetimeField(c, ui.Row(c), cfg.problem != "", cfg.readOnly).Gap(d.Unit() * 2)
 	open := ui.Local(field, "time-open", func() bool { return false })
 	fresh := ui.Local(field, "time-fresh", func() bool { return false })
 	field.Children(func() {
-		segs := ui.Row(c).AlignItems(ui.Center).FocusGroup(ui.Horizontal).Role(ui.RoleGroup).Label(cfg.label)
+		segs := ui.Row(c).AlignItems(ui.Center).Gap(d.Unit() * 1.5).FocusGroup(ui.Horizontal).Role(ui.RoleGroup).Label(cfg.label)
+		if segs.Shortcut(ui.Cmd, ui.KeyC) {
+			c.WriteClipboard(timeText(c, *draft, cfg))
+		}
 		segs.Children(func() {
 			focusNext := false
 			for i, part := range timeParts(cfg) {
@@ -192,84 +205,107 @@ func timeEditor(c *ui.Context, draft *TimeOfDay, cfg timeConfig) (field *ui.Elem
 				if part == timePeriodPart {
 					ui.Box(c).Width(d.Unit())
 				}
-				seg, done := timeSegment(c, draft, part, cfg, &edited)
+				seg, done, segBad := timeSegment(c, draft, part, cfg, &edited)
 				if focusNext {
 					seg.Focus()
-					focusNext = false
 				}
 				focusNext = done
+				if bad == "" {
+					bad = segBad
+				}
 			}
 		})
-		b := datetimeIconButton(c, "clock", msg(c, "time_picker.open"))
+		if cfg.readOnly {
+			return
+		}
+		b := datetimeIconButton(c, "clock", msg(c, "time_picker.open")).Role(ui.RolePopUpButton)
 		if b.Clicked() {
 			*open, *fresh = !*open, true
 		}
 	})
-	if !*open && field.Shortcut(ui.Alt, ui.KeyDown) {
+	if !*open && !cfg.readOnly && field.Shortcut(ui.Alt, ui.KeyDown) {
 		*open, *fresh = true, true
 	}
-	datetimePopup(c, field, open, func() {
+	datetimePopup(c, field, open, cfg.readOnly, func() {
 		if timeColumns(c, draft, cfg, *fresh) {
 			edited = true
 		}
 		*fresh = false
 	})
-	return field, edited
+	return field, edited, bad
 }
 
-// timeSegment draws one focusable segment; done reports a fully typed value.
-func timeSegment(c *ui.Context, draft *TimeOfDay, part timePart, cfg timeConfig, edited *bool) (seg *ui.Element, done bool) {
+// timeLimits returns the lowest and highest value a segment accepts.
+func timeLimits(part timePart, cfg timeConfig) (lo, hi int) {
+	switch {
+	case part != timeHourPart:
+		return 0, 59
+	case cfg.hour12:
+		return 1, 12
+	}
+	return 0, 23
+}
+
+// timeSegment draws one segment; done reports a complete valid entry, bad an invalid one.
+func timeSegment(c *ui.Context, draft *TimeOfDay, part timePart, cfg timeConfig, edited *bool) (seg *ui.Element, done bool, bad string) {
 	k := Tokens(c)
 	d := Density(c)
 	name := msg(c, timePartNames[part])
 	if cfg.label != "" {
 		name = cfg.label + ": " + name
 	}
-	seg = ui.Box(c).Focusable().FocusRing(false).Role(ui.RoleStepper).Label(name).
-		Padding(d.Unit()/2, d.Unit()).Radius(theme.ControlRadius).MinWidth(theme.BodySize * 1.6).Center()
+	seg = ui.Box(c).Focusable().Role(ui.RoleStepper).Label(name).
+		Padding(0, d.Unit()).Radius(theme.ControlRadius).MinWidth(theme.BodySize * 1.6).Shrink(0).Center()
+	internal.Ring(seg, k.Focus, theme.ControlRadius)
 	typed := ui.Local(seg, "time-typed", func() string { return "" })
+	badText := ui.Local(seg, "time-bad", func() string { return "" })
+	badFor := ui.Local(seg, "time-bad-for", func() TimeOfDay { return TimeOfDay{} })
 	if !seg.Focused() {
 		*typed = ""
 	}
+	if *badFor != *draft {
+		*badText = ""
+	}
 	set := func(t TimeOfDay) {
+		*badText = ""
 		if t != *draft {
 			*draft = t
 			*edited = true
 		}
 	}
 	t := *draft
-	step := func(dir int) {
-		switch part {
-		case timeHourPart:
-			t.Hour = (t.Hour + dir + 24) % 24
-		case timeMinutePart:
-			t.Minute = timeStep(t.Minute, cfg.minuteStep, dir)
-		case timeSecondPart:
-			t.Second = timeStep(t.Second, cfg.secondStep, dir)
-		case timePeriodPart:
-			t.Hour = (t.Hour + 12) % 24
+	lo, hi := timeLimits(part, cfg)
+	if !cfg.readOnly {
+		switch {
+		case seg.Shortcut(0, ui.KeyUp):
+			set(timeStepPart(t, part, cfg, 1))
+		case seg.Shortcut(0, ui.KeyDown):
+			set(timeStepPart(t, part, cfg, -1))
 		}
-		set(t)
-	}
-	switch {
-	case seg.Shortcut(0, ui.KeyUp):
-		step(1)
-	case seg.Shortcut(0, ui.KeyDown):
-		step(-1)
-	}
-	if part == timePeriodPart {
-		if seg.Shortcut(0, ui.KeyA) && t.Hour >= 12 || seg.Shortcut(0, ui.KeyP) && t.Hour < 12 {
-			t.Hour = (t.Hour + 12) % 24
-			set(t)
-		}
-	} else {
-		for n := range 10 {
-			if seg.Shortcut(0, ui.Key0+ui.Key(n)) {
-				done = timeType(typed, n, part, cfg, &t)
+		t = *draft
+		if part == timePeriodPart {
+			if seg.Shortcut(0, ui.KeyA) && t.Hour >= 12 || seg.Shortcut(0, ui.KeyP) && t.Hour < 12 {
+				t.Hour = (t.Hour + 12) % 24
 				set(t)
 			}
+		} else {
+			for n := range 10 {
+				if !seg.Shortcut(0, ui.Key0+ui.Key(n)) {
+					continue
+				}
+				v, ok, complete := timeType(typed, n, lo, hi)
+				switch {
+				case ok:
+					set(timeWithPart(t, part, v, cfg))
+					done = complete
+				case complete:
+					*badText, *badFor = fmt.Sprintf("%02d", v), *draft
+					slog.Debug("mujica: time_picker invalid segment", "part", int(part), "typed", v)
+				}
+			}
 		}
 	}
+	t = *draft
 	text := ""
 	switch part {
 	case timeHourPart:
@@ -284,16 +320,64 @@ func timeSegment(c *ui.Context, draft *TimeOfDay, part timePart, cfg timeConfig,
 	case timePeriodPart:
 		text = timePeriod(c, t.Hour)
 	}
+	if *badText != "" {
+		text = *badText
+		bad = fmt.Sprintf(msg(c, "time_picker.part_range"), msg(c, timePartNames[part]), lo, hi)
+	}
+	seg.Description(timeSegmentDescription(c, part, text, lo, hi)).Error(cfg.problem)
 	fg := k.Text
 	switch {
-	case seg.Focused():
+	case *badText != "":
+		fg = k.Danger
+	case seg.Focused() && !cfg.readOnly:
 		seg.Background(k.Accent)
 		fg = k.OnAccent
+	case seg.Focused():
+		seg.Background(k.Selection)
 	case seg.Hovered():
 		seg.Background(k.SurfaceHover)
 	}
 	seg.Children(func() { ui.Text(c, text).TextColor(fg).FontFeatures("tnum").SingleLine() })
-	return seg, done
+	return seg, done, bad
+}
+
+// timeSegmentDescription gives assistive technology a segment's value and range.
+func timeSegmentDescription(c *ui.Context, part timePart, text string, lo, hi int) string {
+	if part == timePeriodPart {
+		return text
+	}
+	return fmt.Sprintf(msg(c, "time_picker.segment"), strings.TrimSpace(text), lo, hi)
+}
+
+// timeStepPart steps one segment of t by dir, wrapping round its cycle.
+func timeStepPart(t TimeOfDay, part timePart, cfg timeConfig, dir int) TimeOfDay {
+	switch part {
+	case timeHourPart:
+		t.Hour = (t.Hour + dir + 24) % 24
+	case timeMinutePart:
+		t.Minute = timeStep(t.Minute, cfg.minuteStep, dir)
+	case timeSecondPart:
+		t.Second = timeStep(t.Second, cfg.secondStep, dir)
+	case timePeriodPart:
+		t.Hour = (t.Hour + 12) % 24
+	}
+	return t
+}
+
+// timeWithPart sets one segment of t to v, keeping the period on a 12-hour clock.
+func timeWithPart(t TimeOfDay, part timePart, v int, cfg timeConfig) TimeOfDay {
+	switch part {
+	case timeHourPart:
+		if cfg.hour12 {
+			v = v%12 + t.Hour/12*12
+		}
+		t.Hour = v
+	case timeMinutePart:
+		t.Minute = v
+	case timeSecondPart:
+		t.Second = v
+	}
+	return t
 }
 
 // timeStep moves v to the next multiple of step in dir, wrapping within an hour.
@@ -307,42 +391,22 @@ func timeStep(v, step, dir int) int {
 	return (v - step + 60) % 60
 }
 
-// timeType adds digit n to a segment's typed digits and reports when the segment is complete.
-func timeType(typed *string, n int, part timePart, cfg timeConfig, t *TimeOfDay) bool {
-	lo, hi := 0, 59
-	if part == timeHourPart {
-		hi = 23
-		if cfg.hour12 {
-			lo, hi = 1, 12
-		}
+// timeType appends digit n; reports value, validity and completion.
+func timeType(typed *string, n, lo, hi int) (v int, ok, complete bool) {
+	s := *typed + strconv.Itoa(n)
+	if len(s) > 2 {
+		s = strconv.Itoa(n)
 	}
-	s := *typed + fmt.Sprint(n)
 	v, err := strconv.Atoi(s)
 	if err != nil {
 		panic(err)
 	}
-	if len(s) > 2 || v > hi {
-		s, v = fmt.Sprint(n), n
+	complete = len(s) == 2 || v*10 > hi
+	if complete {
+		s = ""
 	}
 	*typed = s
-	if v >= lo {
-		switch part {
-		case timeHourPart:
-			if cfg.hour12 {
-				v = v%12 + t.Hour/12*12
-			}
-			t.Hour = v
-		case timeMinutePart:
-			t.Minute = v
-		case timeSecondPart:
-			t.Second = v
-		}
-	}
-	if len(s) == 2 || n*10 > hi && len(s) == 1 {
-		*typed = ""
-		return true
-	}
-	return false
+	return v, v >= lo && v <= hi, complete
 }
 
 // timeColumns lists choosable values per segment and reports whether a choice edited *draft.
diff --git a/time_picker_test.go b/time_picker_test.go
index a5eb6a8..c6976d7 100644
--- a/time_picker_test.go
+++ b/time_picker_test.go
@@ -143,7 +143,7 @@ func TestTimePickerRejectsBadOptions(t *testing.T) {
 
 func TestTimePickerSnapshot(t *testing.T) {
 	a, b := TimeOfDay{9, 30, 0}, TimeOfDay{21, 5, 40}
-	snapshot(t, "time_picker", 480, 80, func(c *ui.Context) {
+	snapshot(t, "time_picker", 520, 80, func(c *ui.Context) {
 		ui.Row(c).Padding(16).Gap(16).Children(func() {
 			TimePicker(c, &a, TimePickerOptions{})
 			TimePicker(c, &b, TimePickerOptions{Hour12: true, Seconds: true})
diff --git a/time_range_picker.go b/time_range_picker.go
index 4776748..3a03486 100644
--- a/time_range_picker.go
+++ b/time_range_picker.go
@@ -9,7 +9,7 @@ import (
 	"mujicaui/theme"
 )
 
-// TimeRange is a start and an end time of day. End before Start means it ends the next day.
+// TimeRange is a span of day; End before Start means next day.
 type TimeRange struct {
 	Start, End TimeOfDay
 }
@@ -28,15 +28,16 @@ type TimeRangePickerOptions struct {
 	// AllowOvernight accepts an end before the start, meaning the next day.
 	AllowOvernight bool
 	Disabled       bool
+	// ReadOnly keeps both ends focusable and copyable but blocks edits.
+	ReadOnly bool
 	// Label names the pair for assistive technology.
 	Label string
 }
 
-// TimeRangePicker edits a start and an end time. It writes *value only when both ends are valid
-// and the end follows the start, or crosses midnight with AllowOvernight.
+// TimeRangePicker writes *value only when the range is valid.
 func TimeRangePicker(c *ui.Context, value *TimeRange, opts TimeRangePickerOptions) DateTimeResult {
 	cfg := timePickerConfig("TimeRangePicker", TimePickerOptions{Seconds: opts.Seconds, Hour12: opts.Hour12,
-		MinuteStep: opts.MinuteStep, SecondStep: opts.SecondStep, Min: opts.Min, Max: opts.Max})
+		MinuteStep: opts.MinuteStep, SecondStep: opts.SecondStep, Min: opts.Min, Max: opts.Max, ReadOnly: opts.ReadOnly})
 	if !value.Start.Valid() || !value.End.Valid() {
 		panic(fmt.Sprintf("mujica: TimeRangePicker value %v is not a pair of times", *value))
 	}
@@ -53,32 +54,37 @@ func TimeRangePicker(c *ui.Context, value *TimeRange, opts TimeRangePickerOption
 	seen := ui.Local(col, "time-range-seen", func() TimeRange { return *value })
 	problem := ui.Local(col, "time-range-error", func() string { return "" })
 	if *seen != *value {
-		*draft, *seen, *problem = *value, *value, ""
+		*draft, *seen = *value, *value
 	}
 	changed := false
 	col.Children(func() {
-		edited := false
+		edited, bad := false, ""
 		ui.Row(c).Gap(d.Unit() * 2).AlignItems(ui.Center).Children(func() {
 			start, end := cfg, cfg
 			start.label, end.label = msg(c, "time_range_picker.start"), msg(c, "time_range_picker.end")
-			start.invalid, end.invalid = *problem != "", *problem != ""
-			if _, e := timeEditor(c, &draft.Start, start); e {
-				edited = true
-			}
+			start.problem, end.problem = *problem, *problem
+			_, e1, b1 := timeEditor(c, &draft.Start, start)
 			ui.Text(c, "–").TextColor(k.TextMuted).Role(ui.RoleNone)
-			if _, e := timeEditor(c, &draft.End, end); e {
-				edited = true
+			_, e2, b2 := timeEditor(c, &draft.End, end)
+			edited, bad = e1 || e2, b1
+			if bad == "" {
+				bad = b2
 			}
 			if draft.Overnight() && opts.AllowOvernight {
-				ui.Text(c, msg(c, "time_range_picker.next_day")).FontSize(theme.CaptionSize).TextColor(k.AccentText)
+				ui.Text(c, msg(c, "time_range_picker.next_day")).FontSize(FontSize(c, theme.CaptionSize)).TextColor(k.AccentText)
 			}
 		})
-		if edited {
-			*problem = timeRangeProblem(c, *draft, cfg, opts.AllowOvernight)
-			if *problem == "" && *draft != *value {
-				slog.Debug("mujica: time_range_picker change", "from", *value, "to", *draft)
-				*value, *seen, changed = *draft, *draft, true
-			}
+		p := bad
+		if p == "" {
+			p = timeRangeProblem(c, *draft, cfg, opts.AllowOvernight)
+		}
+		if p != *problem {
+			*problem = p
+			c.Invalidate()
+		}
+		if edited && p == "" && *draft != *value {
+			slog.Debug("mujica: time_range_picker change", "from", *value, "to", *draft)
+			*value, *seen, changed = *draft, *draft, true
 		}
 		datetimeError(c, *problem)
 	})
diff --git a/year_picker.go b/year_picker.go
index b607152..f6b990d 100644
--- a/year_picker.go
+++ b/year_picker.go
@@ -17,12 +17,13 @@ type YearPickerOptions struct {
 	// Today marks the current year; zero uses the system clock.
 	Today    Date
 	Disabled bool
+	// ReadOnly keeps the field focusable and copyable but blocks the popup and clearing.
+	ReadOnly bool
 	// Label names the field for assistive technology.
 	Label string
 }
 
-// YearPicker chooses a year into *value, zero meaning none, from a decade page.
-// Arrows move by year and row, PageUp and PageDown by decade.
+// YearPicker chooses a year into *value from a decade page; zero is none.
 func YearPicker(c *ui.Context, value *int, opts YearPickerOptions) DateTimeResult {
 	if *value < 0 || opts.Min < 0 || opts.Max < 0 || opts.Min != 0 && opts.Max != 0 && opts.Min > opts.Max {
 		panic(fmt.Sprintf("mujica: YearPicker value %d or range %d..%d is not valid", *value, opts.Min, opts.Max))
@@ -43,7 +44,7 @@ func YearPicker(c *ui.Context, value *int, opts YearPickerOptions) DateTimeResul
 	}
 	col, picked, ok, cleared := datetimeGridPicker(c, datetimeGridField{
 		text: text, placeholder: msg(c, "year_picker.placeholder"), label: label,
-		clearable: opts.Clearable, hasValue: *value != 0, disabled: opts.Disabled, home: home,
+		clearable: opts.Clearable, hasValue: *value != 0, disabled: opts.Disabled, readOnly: opts.ReadOnly, home: home,
 	}, datetimeGridConfig{
 		pageOf:  func(o int) (int, int) { return decade(o) - 1, 12 },
 		cols:    3,