Daylight Savings Time Incorrect for Indiana in WordPress 6

[midipedalboards]

Hello,

Don’t know how long this has existed as an issue because I’ve never had any reason to question it until now.

Using a plugin that echos the date a task was completed at approx 11:30 PM Indianapolis Indiana time on May 27, 2022 the resulting echo output of the date as May 28, 2022.

So I checked my server setting at it was set correctly. I also check the WordPress admin area:

Settings > General > Timezone

which is set to Indiana - Indianapolis (which is correct for me) and I see where it says right below that:

“ Universal time is 2022-05-28 03:56:26. Local time is 2022-05-27 23:56:26.

This timezone is currently in daylight saving time.
This timezone does not observe daylight saving time.”

Indiana does recognize Daylight Savings Time and has since April 6, 2016

Verified here: ​https://faqs.in.gov/hc/en-us/articles/115005225448-Indiana-Time-Zone-Information

[midipedalboards]

Screenshot of the daylight savings time erroneous information

[sabernhardt]

my timezone settings, about 90 minutes later

[sabernhardt]

Thanks for the report!

My settings did not match yours. Could you check again within an hour before and after midnight?

I thought it might relate to the fact that the details do not update until you Save Changes, but saying that the location is in DST and does not observe it makes no sense in any timezone :)

[Rarst]

WordPress pulls time zones information from PHP. If the data is incorrect, it is likely that PHP instance and/or its time zones database is outdated or otherwise invalid.

[zodiac1978]

I suspect that the server does not have the timezones installed correctly.
​https://hackage.haskell.org/package/tzdata

[iStag]

I also encountered the same error under Xampp 8.1.2
I reinstall WordPress every month for my students and the error first appeared to me two weeks ago with the new version WP 6. Before that in the last 4-5 months we used the same Xampp environment and had no timezone problem so far

[Rarst]

I've run this through bunch of PHP versions and there is an issue with reporting future transitions on PHP 8.1.0 to 8.1.5 inclusive. See ​https://3v4l.org/dT94b

As above, there is nothing we can do about it on WordPress level. We just work with data as provided by PHP language.

Just for completeness, I've looked at changes history and related code had no changes in 3 years, so any observations linking it to WP 6 are coincidence.

Related #53780

[Rarst]

Duplicate of #53780.