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What is British Summer Time and British Winter Time?

 

The time in the United Kingdom is different from Beijing time in China. China has only one time, which is Beijing time, running 24 hours a day. However, the United Kingdom has two times: British Summer Time and British Winter Time.

 

During British Summer Time, there is a 7-hour time difference with China, while during British Winter Time, there is an 8-hour time difference with China.

 

What are British Summer Time and British Winter Time? In order to overcome the confusion caused by different times, the International Meridian Conference was held in Washington in 1884. It divided the world into 24 time zones (12 in the east and 12 in the west). The conference designated the Royal Observatory in Greenwich, London (located in Greenwich Park) as the zero time zone, and the other zones were divided into Eastern Zones 1-12 and Western Zones 1-12. The global standard time is based on the Greenwich Observatory, known as Greenwich Mean Time.

 

Each time zone spans 15 degrees of longitude, which corresponds to a difference of 1 hour. The final Eastern and Western Zones, Zone 12, each spans 7.5 degrees of longitude, with the 180th meridian serving as the boundary between the east and the west. The time on the central meridian of each time zone is the unified time used within that zone, known as local time. The time difference between adjacent time zones is 1 hour.

 

For example, China (GMT+8) is 1 hour behind its neighboring country Japan (GMT+9). So when it is 3 p.m. in Beijing, it is 4 p.m. in Japan. China is also 1 hour ahead of its neighboring country Thailand (GMT+7). For instance, when it is 3 p.m. Beijing time, it is 2 p.m. in Thailand.

 

Therefore, since China is in GMT+8, the standard time difference between the UK and China is 8 hours. This means that when it is 3 p.m. on January 1st in China, it is 7 a.m. on January 1st in the UK.

 

Due to the longer daylight hours in summer and shorter daylight hours in winter in the UK, the standard time in the UK is adjusted one hour ahead during the summer, changing from GMT to GMT+1. So when it is 3 p.m. on January 1st in China, it is 8 a.m. on January 1st in the UK. This adjustment results in a time difference of only 7 hours with China, and this adjusted time is called British Summer Time. The original standard time, also known as GMT, is referred to as British Winter Time.

 

Why does the UK make this deliberate adjustment? The main reasons are energy conservation, environmental protection, and reminding people to go to bed and wake up early, not to waste daylight when there is sunshine. Therefore, the English term for this daylight-saving practice is "Daylight Saving Time."

 

During the UK summer, around 8-9 p.m., it still looks like 5-6 p.m. in China. In the UK winter, around 4 p.m., it gets dark like midnight.

 

Apart from the UK, other regions such as the United States, Australia, Canada, New Zealand, and various European countries also observe Daylight Saving Time.

British Summer Time Implementation:

British Summer Time begins on the last Sunday of March each year and ends on the last Sunday of October. The last Sunday of October marks the beginning of British Winter Time. While electronic watches do not adjust automatically, electronic devices such as phones and computers connected to the internet will adjust the time automatically. Therefore, during the period from the end of March to the end of October, it is important to pay attention to the time on Sundays and avoid being late for classes.

 

For example, in 2019, British Summer Time started on March 31 and ended on October 26, with British Winter Time starting on October 27. In 2020, British Summer Time was observed from March 29 to October 24, and British Winter Time began on October 25. For other years, you can refer to a calendar for the specific dates.

 

China's Implementation of Daylight Saving Time:

China implemented Daylight Saving Time for a period of six years, from 1986 to 1991. However, it was only observed in the northeastern and northern regions of China. It started at 2 a.m. on the first Sunday in April and ended at 2 a.m. on the first Sunday in September each year. China's Daylight Saving Time involved setting the clocks forward by one hour. After April 5, 1992, Daylight Saving Time was no longer observed in China.

 

The time periods for China's six years of Daylight Saving Time are as follows:

 

1986: April 13 - September 14

1987: April 12 - September 13

1988: April 10 - September 11

1989: April 16 - September 17

1990: April 15 - September 16

1991: April 14 - September 15

 

For individuals born in the northeastern and northern regions of China during the years of Daylight Saving Time, the actual birth time should be adjusted one hour earlier. For example, if someone was born at 2 p.m. during Daylight Saving Time on June 1, 1990, their actual birth time would be 1 p.m. on June 1, 1990.