You are only required to set the time zone or set the date and time if the wireless LAN does not support Network Time Protocol (NTP) or when not connected to a cellular/wireless network.
Go to
Settings
.
Touch
System > Date & time
Touch
Set time automatically
to disable automatic date and time synchronization.
Touch
Set time zone automatically
to disable automatic time-zone synchronization.
Touch
Date
to select the date in the calendar.
Touch
OK
.
Touch
Time
.
Touch the circle, drag to the current hour, and then release.
Touch the circle, drag to the current minute, and then release.