Fix time changing when switching calendar dates

Author: probablykasper

src/lib/DatePicker.svelte

@@ -5,6 +5,8 @@
 		getCalendarDays,
 		type CalendarDay,
 		applyTimePrecision,
+		clampDate,
+		clamp,
 	} from './date-utils.js'
 	import { getInnerLocale, type Locale } from './locale.js'
 	import { createEventDispatcher } from 'svelte'
@@ -68,31 +70,6 @@
 	} else if (value && isDisabledDate?.(value)) {
 		setValue(toValidDate(browseDate, value, min, max, isDisabledDate))
 	}
-	function clamp(d: Date, min: Date, max: Date) {
-		if (d > max) {
-			return cloneDate(max)
-		} else if (d < min) {
-			return cloneDate(min)
-		} else {
-			return cloneDate(d)
-		}
-	}
-	function clampDate(d: Date, min: Date, max: Date) {
-		const limit = clamp(d, min, max)
-		if (limit.getTime() !== d.getTime()) {
-			d = new Date(
-				limit.getFullYear(),
-				limit.getMonth(),
-				limit.getDate(),
-				d.getHours(),
-				d.getMinutes(),
-				d.getSeconds(),
-				d.getMilliseconds(),
-			)
-			d = clamp(d, min, max)
-		}
-		return d
-	}
 
 	/** The date shown in the popup when none is selected */
 	let browseDate = value ? cloneDate(value) : cloneDate(clampDate(defaultDate, min, max))

src/lib/date-utils.ts

@@ -114,20 +114,21 @@ export function toValidDate(
 	if (oldDate > newDate) {
 		adjustDate(adjustedDate, -1, minDate, maxDate, isDisabledDate)
 		if (adjustedDate < minDate) {
-			adjustedDate = cloneDate(minDate)
+			adjustedDate = clampDate(adjustedDate, minDate, maxDate)
 			// Adjusts the date one more time if the min date is disabled, to ensure a valid, enabled date is selected
 			adjustDate(adjustedDate, 1, minDate, maxDate, isDisabledDate)
 		}
-		return adjustedDate
-	}
-	if (adjustedDate >= oldDate) {
+	} else if (adjustedDate >= oldDate) {
 		adjustDate(adjustedDate, 1, minDate, maxDate, isDisabledDate)
 		if (adjustedDate > maxDate) {
-			adjustedDate = cloneDate(maxDate)
+			adjustedDate = clampDate(adjustedDate, minDate, maxDate)
 			// Adjusts the date one more time if the max date is disabled, to ensure a valid, enabled date is selected
 			adjustDate(adjustedDate, -1, minDate, maxDate, isDisabledDate)
 		}
-		return adjustedDate
+	}
+	// Finally, clamp the time
+	if (adjustedDate < minDate || adjustedDate > maxDate) {
+		adjustedDate = clamp(adjustedDate, minDate, maxDate)
 	}
 	return adjustedDate
 }
@@ -148,3 +149,32 @@ function adjustDate(
 		loopCount++
 	}
 }
+
+export function clamp(value: Date, min: Date, max: Date) {
+	if (value > max) {
+		return cloneDate(max)
+	} else if (value < min) {
+		return cloneDate(min)
+	} else {
+		return cloneDate(value)
+	}
+}
+export function clampDate(value: Date, min: Date, max: Date) {
+	const limit = clamp(value, min, max)
+	value = new Date(
+		limit.getFullYear(),
+		limit.getMonth(),
+		limit.getDate(),
+		value.getHours(),
+		value.getMinutes(),
+		value.getSeconds(),
+		value.getMilliseconds(),
+	)
+	if (value > max) {
+		value.setDate(max.getDate())
+	}
+	if (value < min) {
+		value.setDate(min.getDate())
+	}
+	return value
+}