From 69a1c573284e17e987e422241e2d5996fb9d1868 Mon Sep 17 00:00:00 2001
From: Classic298 <27028174+Classic298@users.noreply.github.com>
Date: Sat, 10 Oct 2026 18:15:25 +0200
Subject: [PATCH] fix: calendar event created late in the evening is saved
 ending a day late (#32199)

Creating a calendar event after 23:00 saved it ending on the day after the date picked, so it showed on two days. The new event form pre-fills an end time one hour from now, which falls on the next day, and that next-day end date was kept even when the event was set to other times. The end date now stays on the start date when the end time is later in the day than the start time. An event that ends after midnight or spans several days keeps its end date.

Fixes #31994
---
 src/lib/components/calendar/CalendarEventModal.svelte | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/lib/components/calendar/CalendarEventModal.svelte b/src/lib/components/calendar/CalendarEventModal.svelte
index cf92306f79..357bec7b35 100644
--- a/src/lib/components/calendar/CalendarEventModal.svelte
+++ b/src/lib/components/calendar/CalendarEventModal.svelte
@@ -29,6 +29,7 @@
 	let startTime = '';
 	let endDate = '';
 	let endDayOffset = 0;
+	let overnight = false;
 	let endTime = '';
 	let allDay = false;
 	let location = '';
@@ -76,6 +77,10 @@
 		return new Date(`${dateStr}T${timeStr || '00:00'}`).getTime() * NS;
 	}
 
+	function endsPastMidnight(): boolean {
+		return !allDay && endTime < startTime;
+	}
+
 	function reset() {
 		if (event) {
 			title = event.title;
@@ -118,6 +123,7 @@
 						(24 * 60 * 60 * 1000 * NS)
 				)
 			: 0;
+		overnight = endDayOffset === 1 && endsPastMidnight();
 	}
 
 	$: if (show) reset();
@@ -136,8 +142,9 @@
 		loading = true;
 		try {
 			const startNs = dateTimeToNs(startDate, allDay ? '00:00' : startTime);
+			const endDays = overnight && !endsPastMidnight() ? 0 : endDayOffset;
 			const shiftedEndDate = endDate
-				? nsToDateStr(dateTimeToNs(startDate, '12:00') + endDayOffset * 24 * 60 * 60 * 1000 * NS)
+				? nsToDateStr(dateTimeToNs(startDate, '12:00') + endDays * 24 * 60 * 60 * 1000 * NS)
 				: '';
 			let endNs = shiftedEndDate
 				? dateTimeToNs(shiftedEndDate, allDay ? '23:59' : endTime)