Is it possible to sync my telrad phone system with a time server?

The only way to change the time on the system is by a feature code, as far as I know.

not possible to use a linux script on the system?

Not that I know of. E-magen voice mail OS is linux but it would do nothing. The system time links to the voice mail side.
If the clock on the phone system is not correct after a couple of days. Change the processor. That's where the clock runs form.

I just tested this to confirm that changing the time and date in the E-magen voice mail linux system does not affect the time on the phones. The time is synced back to the phone time in linux the next day when I checked.

The phone system time can be changed at the time set phone and through PCP/EManager in system utilities.