There is an issue with the time in my macbook air
Have you tried resetting the PRAM? 


  Shut down your Mac. Locate the following keys on the keyboard: Command
  (⌘), Option, P, and R. You will need to hold these keys down
  simultaneously in step 4. Turn on the computer. Press and hold the
  Command-Option-P-R keys before the gray screen appears. Hold the keys
  down until the computer restarts and you hear the startup sound for
  the second time. Release the keys.


If this doesn't help, your PRAM battery may need to be replaced. Not a huge deal.