Linux Set Date and Time From a Command Prompt

Show date

date

Set date

date -s "2 OCT 2006 18:00:00"

Or

date --set="2 OCT 2006 18:00:00"

Or

date +%Y%m%d -s "20081128"

Set time

date +%T -s "10:13:13"

Resources :
http://www.cyberciti.biz/faq/howto-set-date-time-from-linux-command-prompt/