Longtime Arc user here, bit of an odd one here that I saw for the second time last week. First, some high-level info:
My home timezone: PST (California)
My travel timezone: HST (Hawaii)
Issue: last week family and I were in Hawaii all week (in the HST timezone). Each day I “favorited” the day in Arc (7 days, April 6-13). These days in the Arc Calendar showed as “Favorites” all week (as expected). Upon returning home (PST timezone) the 7 days I had favorited were no longer favorited (unexpected). Tried force quitting Arc, restarting iPhone, all 7 days remain unfavorited.
I saw this back in early 2023 (when I last traveled internationally) but figured perhaps it was user error on my end. This time around I am very confident that I did indeed ‘favorite’ these 7 days and can confirm they are now unfavorited.
Oh wow, I’ve never noticed this bug before! But now that you describe it, I can imagine how it would happen. And oddly, it should be happening to me too, given I travel to different timezones a lot and also use favourites a lot. I should have noticed it by now!
Anyway, I’ll file a task for it now and get it fixed hopefully in the next update. Thanks for the heads up!
A bit of technical detail for how I think it might be happening: Favouriting a day marks the DaySummary for that day with the favourite flag. DaySummaries are indexed by the day’s date range (ie start of day to end of day). When you change timezones Arc must be incorrectly creating different DaySummaries for the days in question. Presumably it’s not respecting the local time start/end boundaries, and instead expecting to use start/end boundaries based on your current timezone.
Anyway, that should mean it’s an easy one to fix. And I’m overdue for shipping an Arc Timeline update. So hopefully fixed soon!
