Command - /NickServ SET TIMEZONE
Usage   - /NickServ SET TIMEZONE [timezone]
Usage   - /NickServ SET TIMEZONE NONE
This command sets the default timezone for the nick.
The default timezone is GMT.
Note: You must be identified to NickServ in order to use this command.
Example(s):
/NickServ SET TIMEZONE +2h
/NickServ SET TIMEZONE EST
/NickServ SET TIMEZONE NONE