If the event start time is not showing correctly within Bet Angel it is likely that your time zone settings are incorrect on your computer.
Betfair provide the event start time to Bet Angel in GMT. Your computer then converts this to your local time depending upon your time zone settings so that it shows correctly to you. For example, a soccer match that starts at 3.00pm GMT on a Saturday afternoon will start at 4.00pm CET. Your computer makes the adjustment by looking at your time zone settings.
To check your time zone settings go to the Windows control panel, click on 'Date and Time' and check the time zone is set correctly for your location. Remember that if Daylight Savings is in operation then this also needs to be selected.