Weekday of weekly repeating event appears according to event time zone rather than phone time zone.

[xbjfk]

Checklist

• I can reproduce the bug with the latest version given here.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected app version

1.10.3

Affected Android/Custom ROM version

GrapheneOS Android 17

Affected device model

Pixel 10 Pro XL

How did you install the app?

Google Play Store

Which calendar service or provider do you use, if any?

N/A, reproducible on local

Which sync adapter app do you use for calendar synchronization, if any?

N/A, reproducible on local

Steps to reproduce the bug

1. Set your phone time zone to a time zone far ahead of UTC (I used New Zealand - Auckland).
2. Enable "Allow changing event time zones" in settings
3. Create a weekly repeating event in a time zone such that the event would be a day ahead in the phone's time zone - for example, I create an event on October 15 at 12:00 in the America/Los_Angeles time zone (a Thursday)

Expected behavior

The event shows up as repeating on the next day, for example my event should repeat every Friday 07:00, since my phone's time is set to Pacific/Auckland

Actual behavior

Event is stored correctly, with the correct DTSTART, and shows correctly in other calendars, as well as ics RRULE:FREQ=WEEKLY;INTERVAL=1;BYDAY=XX (e.g. TH for my example)
First event is missing. Further events show up as occurring on the weekday of the event's time zone, not phone time zone. Clicking the event, shows up. Clicking the event appears to show the weekday before the set weekday represented in the calendar.
See screen recording.

Screenshots/Screen recordings

screen-20260904-224834-1788518878903.mp4

Additional information

Note this also seems to occur when creating events in another calendar app (e.g. Etar) and syncing them, and the ics export seems fine.