Daylight savings

Hi All,

we have SAP Systems running on Unix and i understand that during daylight savings we will shut down the SAP and DB for 3 hrs and we will bring it back online. The question which i had is i have noticed in the past that the time at the OS changes from 1:59AM PST to 1:00 AM PST , Do we need to do anything at the OS level for the time to change or the server picks it automatically ?

Thanks in advance.

Regards,

Chaitanya