Chapter 10 Install and System Administration for FortiOS 5.0 : Basic Administration : System configuration : Setting the time and date
  
Setting the time and date
For effective scheduling and logging, the FortiGate system date and time should be accurate. You can either manually set the system date and time or configure the FortiGate unit to automatically keep its time correct by synchronizing with a Network Time Protocol (NTP) server.
To set the date and time - web-based manager
1. Go to System > Dashboard > Status.
2. Under System Information > System Time, select Change.
3. Select your Time Zone.
4. Select Set Time and set the FortiGate system date and time.
5. Select OK.
Set the time and date - CLI
config system global
set timezone <zone_value>
end
execute date [<date_str>]
execute time [<time_str>]
 
By default, FortiOS has the daylight savings time configuration enabled. The system time must be manually adjusted after daylight saving time ends. To disable DST, enter the following command in the CLI:
config system global
set dst disable
end
See Also
Using the NTP Server
Configuring FortiGuard