are you referring to to the clock on my windows desktop?
Yes, a system clock out of sync might cause errors and the wallet will process blocks with the wrong timestamp. It happened to me too

I shut the wallet and compouter down for several hours...Just rebooted it. Wallet is still saying it is out of sync...I must admit. This is frustrating.
Isn't the wallet displaying a message like ""Chekpoint is too old, wait for blockchain to download, or notify developers."?
If so, forget about it. It will work nonetheless.
Yes, this is just warning message. But thanks for notification. This will be fixed.