✔ 最佳答案
Suppose it is 12:00AM at Greenwich. Hong Kong is 8:00AM (GMT+8) and New York is 7:00PM(GMT-5) on a previous day.
Faster and slower are not the appropriate words to describe the time difference. Hong Kong is 8 hours ahead of GMT and New York is 5 hours behind GMT. When it is 8:00AM Dec17 in Hong Kong, it is 7:00PM Dec 16 in New York.
To calculate the time difference, take the larger number minus the smaller number. In this case, it is +8 - (-5) = 13. So Hong Kong is 13 hours ahead of New York.
Time of places to the east of Greenwich is ahead it and places to the west of Greenwich is behind it. It is because the earth is rotating eastward. Places to the east of Geenwich see the sun rise before Greenwich.