The formal time zone division includes 24 time zones, and each time zone is represented by an English letter. Each longitude 15 divides a time zone. China's Beijing is located in the East Eighth District, while the United States is located in the West Fifth District to the West Tenth District, with four time zones. The difference between the two places is twelve time zones.
Extended data
Calculated time zone = known time zone-(time zone of known time zone-time zone of time zone to be calculated). (Note: the eastern time zone is positive and the western time zone is negative)
Example 1: It is known that the time in Tokyo (East Ninth District) is 1 May 12:00, so that the district in Beijing (East Eighth District) can be found.
Beijing time =12: 00-(9-8) =11:00, that is, Beijing time is 0:00 on May 6th.
Example 2: Given that Beijing time is 1 May 12:00, find the time zone of London (central time zone).
London time = 12: 00-(8-0) = 4:00, that is, London time is 1 May 4:00.
Example 3: It is known that Beijing time is on May 0 12:00, and the district of new york (West Fifth District) is found.
New york time =12: 00-[8-(-5)] =-1:00+24: 00-1day =23:00, that is, new york time is 23:00 on April 30th. (Note: If the calculated area is negative, 24:00 should be added, and the date should be reduced by one day, that is, May 1 to April 30).
Example 4: Given that new york time is 1 May 12:00, find Tokyo time zone.
Tokyo time =12:00-[(-5)-9] = 26: 00-24: 00+1day =2:00), that is, Tokyo time is 2: 00 on May 2). (Note: When the calculated area is greater than or equal to 24:00, 24:00 shall be subtracted and the date shall be added by one day, that is, May 1 to May 2).
Judging the old and new days depends on two lines, one is the artificial date line-180 international date line, and the other is the natural line-the regional meridian with local time of 0 o'clock.
When crossing the international international date line from west to east, the date should be reduced by 1 day. For example, at 00:30 local time on the 20th, west of international date line International. When crossing the international international date line from west to east, the local time is 00:30 on 19. If you cross the international international date line from east to west, you need to add 1 day.
Baidu encyclopedia-time zone