I’m considering moving from a Mitel system to FreePBX so I’m putting things together to make sure that I can match the configuration I have on the Mitel, one issue is that I have 2 sites with one server, local phones get the correct time for my timezone and remote phones get the correct time for their time zone because I have programmed multiple timezones and I direct each group to the time zone that it belongs to. the question is whether its possible to create multiple time zones for local and remote phones on FreePBX?
For the phones to have the right time and date, you should configure what is their ntp server. This is a setting on the phones and not in FreePBX, if you are provisioning the devices then Tony described what you have to do.
For closing times and other functions of the PBX, I think most time related functions also allow timezone definitions. So if you have two timezone, your would create two time conditions for 9-5pm (for example), and specify each with a different timezone… or one time condition would be for 9-5 and the other 8-4, no TZ required.
For time display on the phones, this is, as mentioned, a phone related thing which can be configured manually on the phone, or via templates in the provisioning module.