Thetime in China follows a single standardtime offset ofUTC+08:00, whereBeijing is located, even though the country spans five geographicaltime zones. It is the largest sovereign nation in the world that officially observes only one time zone.
The nationwide standardized time is namedBeijing Time (BJT;Chinese:北京时间) domestically andChina Standard Time (CST) internationally.[1]Daylight saving time has not been observed since 1991.[2]
China Standard Time (UTC+8) is consistent acrossMainland China,Hong Kong, andMacau. It is also equivalent withTaiwan,Philippines,Singapore,Brunei, most ofMongolia,Malaysia,Irkutsk Time of Russia,Western Australia, andCentral Indonesia.
In the 1870s, the Shanghai Xujiahui Observatory was constructed by a French Catholic missionary. In 1880s officials inShanghai French Concession started to provide a time announcement service using the Shanghai Mean Solar Time provided by the aforementioned observatory for ships into and out ofShanghai. By the end of 19th century, the time standard provided by the observatory had been switched toGMT+08:00.[3] The practice has spread to other coastal ports, and in 1902 the "Coastal Time" was proposed to be the universal time zone for all the coastal ports in China. However, the time zone for the rest of China remained undetermined.
Until 1913, the official time standard for the whole of China was still theapparent solar time of Beijing, the capital of the country at the time. Starting in 1914, theRepublic of China government began adopting the Beijing Local Mean Solar Time as the official time standard. By 1918, five standard time zones had been proposed by the Central Observatory ofBeiyang government of Republic of China, including the Kunlun (UTC+05:30), Sinkiang-Tibet (UTC+06:00), Kansu-Szechwan (UTC+07:00), Chungyuan (UTC+08:00), and Changpai (UTC+08:30).[3]
After the defeat ofBeiyang government in 1928, the mission of the Central Observatory was moved to Nanjing, and the reference time standard used for the construction oftraditional Chinese Calendar was shifted from Beijing Mean Solar Time toUTC+08:00.[3]
In the 1930s, the proposed five time zones had not been fully observed, causing regions in inner China area to adopt their own time standards, resulting in chaos. On 9 March 1939, when the Ministry of the Interior organized a Standard Time Conference in Chongqing, it was decided to adopt the five time zone proposal with slight modification of their borders starting from 1 June, however it was also decided that the entire country would use the Kansu-Szechwan Time (UTC+07:00) during theSecond Sino-Japanese War which began at the time.[3]
Following the end ofWorld War II, the five time zone system was resumed, although there is little information about the historical usage of time in theKunlun andChangpai zones.[citation needed] A further refined system with adjustment to zone assignment in the Northwest part ofGansu was announced in 1947 for adoption in 1948. However, as theChinese Civil War came to its end in 1949–1950, regional governments under the influence of theChinese Communist Party (CCP), other than those in Xinjiang and Tibet, switched to use the same time as Beijing, which isUTC+08:00, and is later known asBeijing Time orChina Standard Time.[3]
There are two independent sources that claim the CCP, and/or the People's Republic of China, were using apparent solar time for Beijing Time before the period between 27 September 1949 and 6 October 1949, and they adopted the time ofUTC+08:00 within that period of time, but the claim is dubious.[4]
Time zone changes in Tibet are undocumented, but Beijing Time was in use until at least the mid-1950s. Between 1969 and 1986, the time zone was switched repeatedly between Xinjiang Time (UTC+06:00) and Beijing Time.[3]
Daylight saving time was observed from 1945 to 1948, and from 1986 to 1991.[3]
In 1997 and 1999,Hong Kong andMacau were transferred to China from theUnited Kingdom andPortugal respectively, being established asspecial administrative regions. Although the sovereignty of the SARs belongs to China, they retain their own policies regarding time zones for historical reasons. Due to their geographical locations, both are within theUTC+08:00 time zone, which is the same as the national standard, Beijing time.
As an illustration of the wide range, the daylight hours (Beijing Time) for the seats of the westernmost (both including and not includingXinjiang due to local customs, see below) and easternmost counties, calculated for the year 2010, are shown here:[5]
| Division | Daylight time | |||
|---|---|---|---|---|
| Location | County | Province | 1 January | 1 July |
| Westernmost | Akto[6] | Xinjiang | 10:16 – 19:44 | 07:34 – 22:26 |
| Westernmost (not including Xinjiang) | Zanda[7] | Tibet | 09:40 – 19:48 | 07:39 – 21:50 |
| Easternmost | Fuyuan[8] | Heilongjiang | 06:54 – 15:18 | 03:05 – 19:08 |
The border withAfghanistan at theWakhjir Pass has the most significant official change of clocks for any international land frontier:UTC+08:00 in China toUTC+04:30 in Afghanistan.
In Xinjiang, two time standards are used in parallel, namely Beijing Time andXinjiang Time.[9][3]
Xinjiang Time, also known as Ürümqi Time (Chinese:乌鲁木齐时间;pinyin:Wūlǔmùqí Shíjiān), is set due to its geographical location in the westernmost part of the country.[10] The time offset isUTC+06:00, which is two hours behindBeijing, and is shared with neighbouringKyrgyzstan.
Some local Xinjiang authorities now use both time standards side by side.[11][12] Television stations schedule programmes in different time standards according to their nature.[3]
The coexistence of two time zones within the same region causes some confusion among the local population, especially when inter-ethnic communication occurs. When a time is mentioned in conversation between Han and Uyghur, it is necessary to either explicitly make clear whether the time is in Xinjiang Time or Beijing Time, or convert the time according to the ethnicity of the other party.[13][14][15] The double time standard is particularly observable inXinjiang Television, which schedules its Chinese channel according to Beijing time and its Uyghur and Kazakh channels according to Xinjiang time.[16]
Regardless, Beijing Time users in Xinjiang usually schedule their daily activities two hours later than those who live in eastern China. As such, stores and offices in Xinjiang are commonly open from 10:00 to 19:00 Beijing Time, which equals 08:00 to 17:00 in Ürümqi Time.[17] This is known as the work/rest time in Xinjiang.[18]
In most areas of Xinjiang, the opening time of local authorities is additionally modified by shifting the morning session 30–60 minutes earlier and the afternoon session 30 minutes later to extend the lunch break for 60–90 minutes, so as to avoid the intense heat during noon time in the area during summer.[12]
Hong Kong andMacau maintain their own time authorities after transfer of sovereigntyin 1997and 1999 respectively. TheHong Kong Time (Chinese:香港時間; Jyutping:hoeng1 gong2 si4 gaan3) andMacau Standard Time[19] (Chinese:澳門標準時間; Jyutping:ou3 mun2 biu1 zeon2 si4 gaan3;Portuguese:Hora Oficial de Macau[20]) are bothUTC+08:00 all year round, thus in line with Beijing time, and daylight saving time has not been used since 1979 in Hong Kong and Macau.[21][22] In Hong Kong,Greenwich Mean Time was adopted as the basis in 1904, and UTC was adopted as a standard in 1972. Before that, local time was determined by astronomical observations atHong Kong Observatory using a 6-inch LeeEquatorial telescope and atransit circle.[23]
Taiwan, which is not governed under the authority of the People's Republic of China (seepolitical status of Taiwan), also uses UTC+08:00, which corresponds well to its longitude.
The territory of thePeople's Republic of China is covered in theIANA time zone database by the following zones. "Asia/Shanghai" is used instead of "Asia/Beijing" because Shanghai is the most populous city in the zone.[24]
Columns marked with * are from the filezone.tab of the database.
| c.c.* | coordinates* | TZ* | comments* | Standard time | Summer time | Notes |
|---|---|---|---|---|---|---|
| CN | +3114+12128 | Asia/Shanghai | Beijing Time | tUTC+08:00 | — | |
| CN | +4348+08735 | Asia/Urumqi | Xinjiang Time | tUTC+06:00 | — | Unofficial |
| HK | +2217+11409 | Asia/Hong_Kong | tUTC+08:00 | — | ||
| MO | +221150+1133230 | Asia/Macau | tUTC+08:00 | — |
The following zones, including Asia/Kashgar, Asia/Chongqing, and Asia/Harbin, are kept in the "backzone" file of the IANA time zone database for backward compatibility.
| c.c.* | coordinates* | TZ* | comments* | Standard time | Summer time | Notes |
|---|---|---|---|---|---|---|
| CN | Asia/Harbin | tUTC+08:00 | — | linked back to Asia/Shanghai | ||
| CN | Asia/Chongqing | tUTC+08:00 | — | linked back to Asia/Shanghai | ||
| CN | Asia/Kashgar | tUTC+06:00 | — | linked back to Asia/Ürümqi |
Urumqi Time (GMT+6) is 2 hours behind Beijing Time
