Recurring Events Not Showing at Correct Time After Changing TimeZone and Navigating Forward/Backward in Time

[nicholascm]

Reduced Test Case

https://codepen.io/nicholascm90/pen/eYogJOV?editors=0010

Do you understand that if a reduced test case is not provided, we will intentionally delay triaging of your ticket?

• I understand

Which connector are you using (React/Angular/etc)?

React

Bug Description

This occurs with no connector (codepen above) and also in my project, react.

Using a recurring event with or without a tzid and setting the timezone prop on FullCalendar, the recurring event initially shows at the correct time adjusted for the timezone, however, navigating forward or backwards it gets out of sync again and shows at the wrong time.

In the codepen, see that the event is set for 10:30 AM, America/New_York:

Steps:

1. Change the timezone to America/Chicago (see recurring event switches to 9:30 AM correctly)
2. Go backwards one day in time, and see that tz is still America/Chicago, but event has moved back to 10:30 AM

My expectation was that it should continue to show at 9:30 AM.

[nicholascm]

This seems to resolve the issue : #5273 (comment)

[acerix]

The timeZone setting works by having the server return the times in the time zone which is included as a URL param, so the events need to be refreshed after changing the timezone.

So it doesn't work with a static list of events in your example, in that case, events specified in local time are assumed to be in the local time initial timeZone setting.

[nicholascm]

Thanks for looking at this @acerix. The behavior is different between the two different kind of events though. In one case, the non-recurring event adjusts properly as a part of the static list, but the issue is with the recurring event not staying adjusted for the timezone.

The linked change is working really well for me for recurring events and fullcalendar is doing the timezone adjustment properly. I made the changes in @fullcalendar/rrule using patch-package.