Confluence calendar event move with DST even if user and calendar uses UTC

[Mohamed Mohamed]

We have a regular event that needs to happen at 5:00pm UTC on the last Sunday of every month.

We created a new calendar set its timezone to Universal, there was no option to choose UTC, and after the calendar is created it appears as "Europe/London (Z)" when you open the Edit dialog.

We have a user who set their timezone in the profile as UTC.

This user created this event, and when that user looks at the calendar it appears as 4:00pm from April to October.

Why does that happen? How can we have an event showing with a consistent time if the user's timezone is set to UTC?

[Humashankar VJ]

Hi @Mohamed Mohamed 

The Confluence Team Calendar's interpretation of the "Universal" timezone setting as "Europe/London (Z)" causes events to shift during daylight saving time (DST).

• Specifically, from April to October, Europe/London observes British Summer Time (UTC+1), which results in a 5:00 PM UTC event being displayed as 4:00 PM local time.
• This occurs because the calendar internally maps "Universal" to "Europe/London (Z)", which follows DST rules.
• Since the user's timezone is set to UTC, which does not observe DST, the calendar applies the DST shift when displaying times.

To get rid, You can either change the calendar timezone to a non-DST-observing timezone like "Etc/UTC", manually adjust the event to re-anchor it to 5:00 PM UTC, or consider using an alternative tool like Google Calendar that supports explicit UTC-based recurring events.

Hope this helps - Happy to help further!!
Thank you very much and have a great one!
Warm regards