You can set the timezone of you main nodeusing teh following method.
1. Login to the main host node.(SSH).
2.check the file /usr/share/zoneinfo/ and confirm which is your timezone(PST,UTC,EST,IST)
3.Now move the file /etc/localtime
mv /etc/localtime /etc/localtime_bk
4.link your timezone to /etc/localtime
ln -s /usr/share/zoneinfo/IST /etc/localtime
Now you may need to synchronize the time using rdate command. If rdate is not available install it with yum.
rdate -s rdate.cpanel.net&