if time in Greenwich is 12:00 noon, find the time of Lahore (Pakistan). The longitude of Lahore is 75 degrees E. The difference of time between Greenwich and Lahore= longitude of Lahore/15 =75/15 = 5hours. Because Lahore is Situated in the east of Greenwich (Prime Meridian), its time would be 5 hours ahead. So 12:00+5 = 17:00 which means 5:00 pm. Note: We would subtract the time difference from the Greenwich time, if the place lies in the west of Greenwich.