You can manually set the server date and time through the interface and enable server time synchronization with a Network Time Protocol (NTP) server.
To adjust the system date and time settings:
You will need to restart your Parallels Plesk Panel server for the time zone change to take effect.
Note for users of Parallels Plesk Panel for Windows: Clear the Automatically adjust clock for daylight saving changes check box, if you do not want Parallels Plesk Panel to automatically adjust the server clock.
Note. Enabling the Synchronize system time function will override any time and date you manually enter in the System Date and Time fields. It is also important to be sure the domain name or IP address you enter for synchronization is a valid NTP server. If not, this function will not work and your server will continue running with its current time settings.