After Selecting the closest major city from the selections, use the A and B column to correct for your local time.
Where #Lg = the base longitude, and #Lt = the base latitude,
and where Lg is your station longitude and Lt is your station latitude, the corrected time is:
Where #Lg, Lg, #Lt, Lt are in decimal degrees.
You need also to pay attention to the value sign of the number.
If you are East or South of the base station, your time will be later than the base station.
If you are West or North of the base station, your time will be earlier than the base station.