Date &Time is very important in Technology.. to make a program run properly like web browsing,Anti Virus Windows Update. Because all program have there synchronize system. some system may not work if your Date and Time is out of Date. Crack Programs need to turn back Date a Year to run it before the Expiration Date or Trial.
Make Sure Your CMOS Battery is on Good Condition, When your Date and Time Turns back after a Restart It means you have a drain CMOS battery, you need a replacement for it.