fix #3701, calculation wrong, added testcase, ics, config (#3702)

fixes #3701 

offset calculation wrong when user looking back at east coast event

added testcase

CHANGELOG.md

@@ -35,6 +35,7 @@ planned for 2025-04-01
 - [calendar] Fix arrayed symbols, #3267, again, add testcase, add testcase for #3678
 - [weather] Fix wrong weatherCondition name in openmeteo provider which lead to n/a icon (#3691)
 - [core] Fix wrong port in log message when starting server only (#3696)
+- [calendar] NewYork event processed on system in Central timezone shows wrong time #3701
 
 ## [2.30.0] - 2025-01-01
 

modules/default/calendar/calendarfetcherutils.js

@@ -662,9 +662,11 @@ const CalendarFetcherUtils = {
 				Log.debug("signs are the same");
 				if (Math.sign(eventDiff) === -1) {
 					//if west, looking at more west
+					//  -350 <-300
 					if (nowDiff < eventDiff) {
 						//-600        -420
-						eventDiff = -(eventDiff - (nowDiff - eventDiff)); //-180
+						//300           -300         -360      +300
+						eventDiff = nowDiff - eventDiff; //-180
 						Log.debug("now looking back east delta diff=", eventDiff);
 					}
 					else {

tests/configs/modules/calendar/chicago-looking-at-ny-recurring.js

@@ -0,0 +1,33 @@
+let config = {
+	address: "0.0.0.0",
+	ipWhitelist: [],
+
+	timeFormat: 24,
+	modules: [
+		{
+			module: "calendar",
+			position: "bottom_bar",
+			config: {
+				fade: false,
+				urgency: 0,
+				dateFormat: "Do.MMM, HH:mm",
+				fullDayEventDateFormat: "Do.MMM",
+				timeFormat: "absolute",
+				getRelative: 0,
+				maximumNumberOfDays: 28,
+				showEnd: true,
+				calendars: [
+					{
+						maximumEntries: 100,
+						url: "http://localhost:8080/tests/mocks/chicago-nyedge.ics"
+					}
+				]
+			}
+		}
+	]
+};
+
+/*************** DO NOT EDIT THE LINE BELOW ***************/
+if (typeof module !== "undefined") {
+	module.exports = config;
+}

tests/electron/modules/calendar_spec.js

@@ -253,6 +253,11 @@ describe("Calendar module", () => {
 			// just
 			await expect(doTestTableContent(".calendar .event", ".time", "29th.Oct, 05:00-30th.Oct, 18:00", first)).resolves.toBe(true);
 		});
+		it("viewing from further west in diff timezones", async () => {
+			await helpers.startApplication("tests/configs/modules/calendar/chicago-looking-at-ny-recurring.js", "22 Jan 2025 14:30:00 GMT-06:00", [], "America/Chicago");
+			// just
+			await expect(doTestTableContent(".calendar .event", ".time", "22nd.Jan, 17:30-19:30", first)).resolves.toBe(true);
+		});
 	});
 
 	describe("one event non repeating", () => {

tests/mocks/chicago-nyedge.ics

@@ -0,0 +1,15 @@
+BEGIN:VEVENT
+DTSTART;TZID=America/New_York:20240918T183000
+DTEND;TZID=America/New_York:20240918T203000
+RRULE:FREQ=WEEKLY;BYDAY=WE
+EXDATE;TZID=America/New_York:20241127T183000
+EXDATE;TZID=America/New_York:20241225T183000
+DTSTAMP:20250122T045443Z
+UID:_@google.com
+CREATED:20240916T131843Z
+LAST-MODIFIED:20241222T235014Z
+SEQUENCE:0
+STATUS:CONFIRMED
+SUMMARY:Derby
+TRANSP:OPAQUE
+END:VEVENT