Is it wrong for all of them?
Pokerstars and those two should record the timezone in the hand history so it should auto adjust without you doing anything. Some sites like Ipoker do not and you have to manually set it Is your clock date and time correct and also importantly is your timezone also correct?
Double check both are correct and if the issue is still happening please attach one of your hand history files for each affected site to a Support Ticket
and tell us what timezone you're in and what the local time was when you played the hands and finally please let us know what version of PostgreSQL you are running.
Note: Adjusting your timezone or time on the PC will not fix previously imported hands