Since many of our users might not have completely migrated from Windows they probably be facing some time issues when they login into Ubuntu & then login back into Windows.
Well thats because Ubuntu treats your default time to be UTC (Universal Time Coordinated or GMT).

So to adjust the time such that the time remains same in both the cases do the following:

1) Press Alt+F2 (remember the shortcut)
2) Type (else copy paste)

gksu gedit /etc/default/rcS

3) Enter the password and a gedit (almost same as Notepad for windows) window will pop up.
4) Search for UTC and set UTC=yes or UTC=no (or accordingly how you wish)
5) Reboot and you are done..!!!!
Happy Synchronization

Note: sudo or gksu both are for running commands as root. gksu is preferred if you want to use GUI.