Hi all,
It’s been some time since the WordPress 5.3 release, but it appears this timezone issue is still affecting ACF users. I sympathize for you, and hope the following info can help.
Unfortunately, this issue is not an ACF bug that can be fixed from our end.
The issue stems from a change in WordPress 5.3 that alters the behavior of the date_i18() function. This function is used in ACF to “format” the saved value based on the field’s settings.
Since the update, WordPress now expects the default timezone to be UTC, which is causing a widespread incompatibility with the date_default_timezone_set() function.
Please read this comment: https://wordpress.org/support/topic/read-this-first-wordpress-5-3-master-list/#post-12124062
The only known solution is to remove any occurrence of the date_default_timezone_set( ) function from your site. This should first be tested, as each website is different and may require additional changes to avoid timezone related date problems.
You may also find some useful info on this announcement here:
https://make.wordpress.org/core/2019/09/23/date-time-improvements-wp-5-3/
Thanks
Elliot
