Zone NAME STDOFF RULES FORMAT [UNTIL]
Pacific/Guam
Time zone identifier: Pacific/Guam
Current civil offset: +10:00 (ChST)
Current DST state: Observing Standard Time
First standard time adoption: Adopted on 1844-12-31
Local Mean Time (LMT): -14:21 based on geographic meridian
Total recorded transitions: 21 transitions across 5 distinct offsets
Aliases (Link targets): Pacific/Saipan
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Historical Offset Step Chart (1880 to Present)
Text summary: Pacific/Guam shifted between 5 distinct offsets from 1844-12-31 through the modern era.
Complete Transition History (21 Transitions)
| UTC Instant | Local Wall Time | Shift | Abbreviation | DST | Effect |
|---|---|---|---|---|---|
1844-12-31T14:21:00Z | 1845-01-01 00:00:00 | -14:21 → +09:39 | LMT | No | gap |
1900-12-31T14:21:00Z | 1901-01-01 00:21:00 | +09:39 → +10:00 | GST | No | gap |
1941-12-09T14:00:00Z | 1941-12-09 23:00:00 | +10:00 → +09:00 | +09 | No | overlap |
1944-07-30T15:00:00Z | 1944-07-31 01:00:00 | +09:00 → +10:00 | GST | No | gap |
1959-06-26T16:00:00Z | 1959-06-27 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1961-01-28T15:00:00Z | 1961-01-29 01:00:00 | +11:00 → +10:00 | GST | No | overlap |
1967-08-31T16:00:00Z | 1967-09-01 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1969-01-25T13:01:00Z | 1969-01-25 23:01:00 | +11:00 → +10:00 | GST | No | overlap |
1969-06-21T16:00:00Z | 1969-06-22 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1969-08-30T15:00:00Z | 1969-08-31 01:00:00 | +11:00 → +10:00 | GST | No | overlap |
1970-04-25T16:00:00Z | 1970-04-26 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1970-09-05T15:00:00Z | 1970-09-06 01:00:00 | +11:00 → +10:00 | GST | No | overlap |
1971-04-24T16:00:00Z | 1971-04-25 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1971-09-04T15:00:00Z | 1971-09-05 01:00:00 | +11:00 → +10:00 | GST | No | overlap |
1973-12-15T16:00:00Z | 1973-12-16 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1974-02-23T15:00:00Z | 1974-02-24 01:00:00 | +11:00 → +10:00 | GST | No | overlap |
1976-05-25T16:00:00Z | 1976-05-26 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1976-08-21T15:01:00Z | 1976-08-22 01:01:00 | +11:00 → +10:00 | GST | No | overlap |
1977-04-23T16:00:00Z | 1977-04-24 03:00:00 | +10:00 → +11:00 | GDT | Yes | gap |
1977-08-27T15:00:00Z | 1977-08-28 01:00:00 | +11:00 → +10:00 | GST | No | overlap |
2000-12-22T14:00:00Z | 2000-12-23 00:00:00 | +10:00 → +10:00 | ChST | No | offset-only |
Notes from the Maintainers
Years on Record
Methodology Note: The 1970 Rule
tzdb guarantees accuracy for timestamps from 1970 onwards. Transitions prior to 1970 represent best-effort historical reconstructions.
australasia(Lines 466 to 467)