Changing Timezone in Ubuntu server.

Step 1: Check

ahmed@server:~# date
Thu Jan 29 02:38:55 EST 2015
ahmed@server:~# more /etc/timezone
US/Eastern

Step 2: Change Timezone setting

ahmed@server:~# dpkg-reconfigure tzdata

Current default time zone: 'Asia/Kolkata'
Local time is now:      Thu Jan 29 13:09:54 IST 2015.
Universal Time is now:  Thu Jan 29 07:39:54 UTC 2015.

ahmed@server:~# date
Thu Jan 29 13:09:57 IST 2015
ahmed@server:~#

Step 3: Also make sure to restart cron service as this will still have the old time.

ahmed@server:~# service crond restart
ahmed@server:~# service nginx restart

And we are done.