I am not aware of your level of computer expertise, so please excuse this if you already know it/have done it.
Bottom RH side of Taskbar, where your clock resides - RIGHT click the time. Click <Adjust Date & Time> - look for < Date & Time> - <Time Zone> - make sure you have the right Time Zone set, use <Change Date & Time> if not.
You can also set it to Internet Time, look for the tab <internet Time> and set that.
If that does not help, or you already know or have done this, I hope someone else can help. Is your Win7 installation a new one? Sometimes it is easy to set the wrong time at Setup.