Question

What is the local time at San Francisco (120°W) when the GMT is 6 AM?

Answer 1

San Francisco is located at 120°W longitude. Since every 15° difference in longitude corresponds to a 1-hour difference in local time from GMT, San Francisco is 8 hours behind GMT (120 ÷ 15 = 8). Therefore, when the GMT is 6 AM, the local time at San Francisco is 10 PM on the previous day. This time difference is because moving westward, clocks are set one hour behind for each time zone crossed.