Historically distinct IANA time zone

Asia/Shanghai

Canonical IANA identifier · Data release 2026c

Local time now +08:00 CST · current offset

Countries: People's Republic of China
GPS reference: 31.23° N, 121.47° E
Data source: IANA asia
Aliases: Asia/Chongqing, Asia/Chungking, Asia/Harbin, PRC
Rule groups: Shang

Beijing Time

Geographic context

Where this clock belongs

The map marks the IANA reference location and associated country, not a time-zone boundary.

World location

Regional context

GPS reference: 31.23° N, 121.47° E. Associated countries: CN.

The Wikipedia link provides additional context; it is not evidence for a historical claim. Transition data comes from the IANA source file.

Notes from the time database

The story behind the clock

These source notes describe a period or rule. They do not, by themselves, establish a causal claim for a particular clock change.

1919–1949

Rule context

According to this news report: on April 11, 1919, newspaper in Shanghai said clocks in Shanghai will spring forward for an hour starting from midnight of that Saturday. The report did not mention what happened in Shanghai thereafter, but it mentioned that a similar trial in Tianjin which ended at October 1st as citizens are told to recede the clock on September 30 from 12:00pm to 11:00pm. The trial at Tianjin got terminated in 1920. The Returns of Trade and Trade Reports, page 711, says "Daylight saving was given a trial during the year, and from the 12th April to the 1st October the clocks were all set one hour ahead of sun time. Though the scheme was generally esteemed a success, it was announced early in 1920 that it would not be repeated."

1948–1949

Transition note

plan

Original IANA source file: asia.

Civil-time record

Recorded changes over time

From 1900 to 1991 · 29 recorded transitions

Show period

Recurring daylight-saving changes are grouped separately when JavaScript is available.

Notable changes

One-off changes and transitions outside the recurring seasonal rhythm.

1900-12-31 23:54+08:00 · CSTStandard time applies
1919-04-13 01:00+09:00 · CDTDaylight saving time begins
1919-09-30 23:00+08:00 · CSTStandard time applies
1940-06-01 01:00+09:00 · CDTDaylight saving time begins
1940-10-12 23:00+08:00 · CSTStandard time applies
1941-03-15 01:00+09:00 · CDTDaylight saving time begins

Browse every recorded transition

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Local time after transition	Offset after	Abbreviation	Rule
1900-12-31 23:54	+08:00	CST	Standard time
1919-04-13 01:00	+09:00	CDT	Daylight saving time
1919-09-30 23:00	+08:00	CST	Standard time
1940-06-01 01:00	+09:00	CDT	Daylight saving time
1940-10-12 23:00	+08:00	CST	Standard time
1941-03-15 01:00	+09:00	CDT	Daylight saving time
1941-11-01 23:00	+08:00	CST	Standard time
1942-01-31 01:00	+09:00	CDT	Daylight saving time
1945-09-01 23:00	+08:00	CST	Standard time
1946-05-15 01:00	+09:00	CDT	Daylight saving time
1946-09-30 23:00	+08:00	CST	Standard time
1947-04-15 01:00	+09:00	CDT	Daylight saving time
1947-10-31 23:00	+08:00	CST	Standard time
1948-05-01 01:00	+09:00	CDT	Daylight saving time
1948-09-30 23:00	+08:00	CST	Standard time
1949-05-01 01:00	+09:00	CDT	Daylight saving time
1949-05-27 23:00	+08:00	CST	Standard time
1986-05-04 03:00	+09:00	CDT	Daylight saving time
1986-09-14 01:00	+08:00	CST	Standard time
1987-04-12 03:00	+09:00	CDT	Daylight saving time
1987-09-13 01:00	+08:00	CST	Standard time
1988-04-17 03:00	+09:00	CDT	Daylight saving time
1988-09-11 01:00	+08:00	CST	Standard time
1989-04-16 03:00	+09:00	CDT	Daylight saving time
1989-09-17 01:00	+08:00	CST	Standard time
1990-04-15 03:00	+09:00	CDT	Daylight saving time
1990-09-16 01:00	+08:00	CST	Standard time
1991-04-14 03:00	+09:00	CDT	Daylight saving time
1991-09-15 01:00	+08:00	CST	Standard time

Where this clock belongs

The story behind the clock

Same clock today, different past

Recorded changes over time

Notable changes