[pauldelbrot]

The forum seems to have lost the ability to show correctly offset time stamps. It was working all winter, but the problems started when it failed to automatically adjust for daylight savings ending this spring. It began showing me times that were an hour off. I eventually dug up the setting and clicked "auto detect", which put it correct again ... until today. I just found it claiming an image I just uploaded is from an hour in the future. Doing the auto detect again changed the offset for displaying time stamps for my account from -0500 to -0600, after which I reloaded the main page, and it still is showing the same image as uploaded an hour in the future.

So, a) it somehow got "sprung forward" a second time, this time on its own, and on the wrong date, and b) even when auto detect shows it being changed it no longer seems to "take".

This is an odd one, since it's fairly simple to get it right (just geo-locate user IP, set their profile's TZ offset from UTC appropriately, and show them times in their own local time, which is what I think the "auto detect" tries to do) and it would take real effort to have it springing forward twice in a single spring ... though, perhaps if two different modules or add-ins or whatever were added to SMF that both try to do time zone offsets, that might conceivably result in a "double dose" of things like DST changes. (Though, on separate days weeks apart? ... oh no, don't tell me, one of these plugins is naive enough to assume that every time zone springs forward exactly on the equinox or something?)

Linkback: https://fractalforums.org/forum-help-and-support/31/time-zone-settings-broken/1104/

[claude]

DST is complicated, the dates are not uniform across countries, and the formulas change over time, so any coded solution will rot.  Here are two possibly relevant cases:

[where	DST start	DST stop
United Kingdom	Sunday, 25 March	Sunday, 28 October
United States	Sunday, 11 March	Sunday, 4 November

https://www.timeanddate.com/time/dst/2018.html more here