Sounds like a time zone issue...
Make sure the time on your phone is set to the correct timezone, and is using the correct daylight-saving-time setting. You can find this in the Advanced menu of the Time and Date section of the Settings menu on your phone. For example, if the time is 8am, and you're in 1-hour daylight saving time (like GMT in British Summer Time - where are you from?), set your phone to 7am, and the Daylight Saving Time setting to +1 hour.
I think your computer will do this all automatically, assuming you select the correct time zone in the Date and Time settings in System Preferences.
Might solve it...