Problem is the one several post already has displayed : I've updated one of our wordpress from 4.6.1 to last version. Local time of server is not UTC and WordPress inside general options show a UTC time equal to server local time instead of server UTC time (and of course, local time displayed by Wordpress is also shifted).
All the post I've read say the same thing : server needs to be in UTC. For several reasons (main is we have a lot of websites on this server, all of them not running on WP), we don't want to modify the time of server to be in UTC.
Is there a possibility to "tell" to WordPress that the time it thinks UTC is not UTC but in a local timezone ?
Any idea to solve this problem ?