Change the Time Zone in Raspberry Pi Raspbian OS.
1. From the command console (launch LXTerminal if in GUI desktop mode).
2. Type sudo raspi-config and press Enter
3. Down arrow to 4 Internationalisation Options and press Enter.
4. Highlight 2 Change Timezone and press Enter key.
5. Follow screen directions to change country and time zone.
6. When done, use Tab to move to Finish and press Enter.
7. Type Exit in the LXTerminal command box.
Note: the Raspberry Pi does not have an on-board, real-time clock. Time and date are automatically set from a network time server if the Pi running Raspbian is connected to the internet. For this, the time zone is important.
Alternatively, if the Pi is not connected to the internet, the time/date can be set manually from within the command console (LXTerminal) using the following command format as example.
sudo date -s “Wed Aug 19 14:28:30 2015”
However, once shut down, Pi will not update the date/time, and on next boot, will recall its last known date/time from the previous shutdown.