The national average time in China is Beijing time, that is, the time in East Eight Districts.

Time in America is more complicated. The 48 states in the United States have four time zones, namely Pacific Time, Mountain Time, Central Time and Eastern Time from west to east. And Alaska (state) time.

Therefore, continents in different time zones use different times. For example, new york is in the West Fifth District, which is 13 hours later than Beijing time, and west eight District, California, which is 16 hours later than San Francisco, Alaska, that is, the West Ninth District is 17 hours later than the West Tenth District, and Hawaii-Aleutian is 18 hours later than the West Tenth District. Western mountainous area, west eight District.

Extended data:

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When we travel abroad by plane, due to the change of time difference, the biological clock in the human body will be chaotic and make people feel dizzy. It's medically called jet lag syndrome.

In severe cases, symptoms such as headache, tinnitus, palpitation, nausea, abdominal pain, diarrhea, decreased judgment and attention may occur. Retrospective study shows that the incidence of puberty is the highest (Steering Committee of Diagnostic Classification, ThorpyM. J: International Classification of Sleep Disorders: Diagnostic and Coding Manual).

American Sleep Disorders Association, Rochester, 1990), this circadian rhythm-related adolescent sleep disorder makes it difficult for patients to adapt to society and hinders their game ability (Kajimura et al.: Japanese Journal of Clinical Medicine. 56 issues, 2 volumes, 404 pages 1998) So when traveling abroad by plane, you can use the following methods:

1, drink plenty of water on the plane, and don't drink alcoholic beverages to avoid dehydration in the body, which will aggravate the influence of jet lag.

2, should wear loose clothes, so that blood flows in the body.

3. Walk around the cabin as much as possible to stretch your muscles during the flight.

4. A patent from Europe claims that 25-50mg/ day of natural astaxanthin can be used to prevent this jet lag (patent number EP 1283038).

How to calculate the time in 24 time zones

Sometimes the area table in the textbook. When doing time zone problems, count them one by one and slowly explore the rules.

For example, Beijing (120' East Eighth District) No.6 at 8 o'clock. Excuse me, what time is it in new york (75' West Fifth District)?

Count the squares in the cross-reference table one by one (excluding the one where Beijing is located), and add the number in the east, * * 1 1, so 8+ 1 19. In the process of counting, new york crossed the border to the east (the opposite is true when it crossed a Japanese border to the west).

Method 2: You can also use Western Digital, * *13, minus 8- 13=-5, with a negative sign to prove that new york was yesterday, and the side 24-5= 19, of course, there is no 5th.

(If it is greater than 24, minus 24 plus one day)

Also note that 1 has a time zone called Central Time Zone 2. East 12 and west 12 belong to the same zone. )

How to calculate the possible influence of jet lag on you;

If you fly east, the jet lag may be heavier, so your body's ability to adapt to a shorter time is not as good as its ability to adapt to a longer time.

You can use the following formula to roughly calculate how many days your jet lag may affect you. ? The number of time zones crossed after flying west is divided by 2.

The number of time zones crossed after flying eastward is divided by 1.5.

For example, when an airplane flies eastward from Shanghai, China to the eastern part of the United States, * * * crosses 1 1 time zone: 13 divided by 1.5= flight time difference lasting about 9 days.

Baidu encyclopedia-time difference between China and the United States