Working with advertising, ads, and audiences is much easier if you have a "working" time zone set in your ad account. This can be, for example, your own or the CA/geo zone with which you plan to work. That said, such a trivial action as changing the time zone in Facebook causes great difficulty for webmasters.
How do I know the time zone of the AD Account?
You can see in the Cabinet section under the name of the cabinet you want, for example, GTM - 7 means that this cabinet has a -7 time zone.
How do I change my time zone?
The time zone of the office can be changed when linking the card (if you haven't changed your time zone before in FB, because FB may have restrictions on this change).
Simply, when you tie the card to this cabinet, set the "Set ad accaunt time zone" slider to active, select the desired time zone and continue tying the card, the time zone (if FB has not set any limitations on the time zone) will be set in the "Set ad accaunt time zone" position.