Antonio D.

Daniil Zhitnitskii

This plugin provides network administrators ability to set same time zone over all blogs in multisite installation in one click, and also it restricts changes of timezone from local blogs settings.
*Based on: https://premium.wpmudev.org/forums/topic/set-default-timezone-for-new-blogs-in-the-network
Only works with multisite installation!
Gutenberg: compatible!
<h3>Disclaimers</h3>
The Simple default timezone plugin is supplied “as is” and all use is at your own risk.

Simple default timezone

As Super Administrator, you can set the (default) timezone for all blogs.

ezraverheijen

This lightweight plugin can be used if the scheduled post feature is not working for you (missed scheduled post errors), and you host your site in a European country using CEST in the summer and CET during the winter.

WP TimeZone

Takes care of publishing posts that missed their schedule, for CET/CEST time zones only.

Simple default timezone vs WP TimeZone