Time zone · Oceania
CHAST
Chatham Standard Time
Chatham Standard Time (CHAST) is used only in New Zealand’s Chatham Islands, which follow a unique UTC+12:45 standard offset. During DST, clocks shift forward to +13:45, making it one of the only regions in the world with a non-standard quarter-hour offset and daylight saving.
Thursday, October 15, 2026
Current offset
UTC+13:45
Daylight · +1345
Daylight saving
Active
Reverts 4 Apr 2027
IANA zones
1
1 observe DST, 0 don't
DST offset
UTC+13:45
CHADT · +1h
About CHAST
Standard time, with a summer shift.
Chatham Standard Time (CHAST) is used only in New Zealand’s Chatham Islands, which follow a unique UTC+12:45 standard offset. During DST, clocks shift forward to +13:45, making it one of the only regions in the world with a non-standard quarter-hour offset and daylight saving.
DST schedule · CHAST · CHADT
2027 Sunday · clocks fall back
Clocks fall back by one hour · in 6 months.
One year, two clocks
IANA zones · the technical identifiers
The zone that resolve to CHAST.
For software, always store the IANA identifier — never the abbreviation alone. The database keeps these zones distinct because their rules can, and historically did, diverge.
Where CHAST is used
One country.
Convert
CHAST to the world's clocks.
Frequently asked questions
Common questions about CHAST, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].
- Why does the Chatham Islands use a +12:45 offset?
- The Chatham Islands lie about 800 km east of mainland New Zealand, and their clocks are set 45 minutes ahead of the mainland’s, giving the distinctive UTC+12:45 standard offset.
- Is the Chatham Islands the only place with a 45-minute offset?
- No. Nepal also uses a 45-minute offset (UTC+05:45), but the Chatham Islands are the only place with a 45-minute offset that also observes daylight saving.
- Does CHAST observe daylight saving time?
- Yes, CHAST observes DST, shifting forward by one hour during the New Zealand summer, resulting in a +13:45 offset during that period.
- When does DST start and end in CHAST?
- In the Chatham Islands, DST starts on the last Sunday of September at 02:45, when clocks jump to 03:45, and ends on the first Sunday of April at 03:45, when clocks go back to 02:45 (local time).
- How does living on CHAST affect daily life?
- The islands are among the first inhabited places to start each new day, and the unusual offset requires extra attention when scheduling with the mainland or international partners.
- What abbreviation is used for CHAST?
- CHAST stands for Chatham Standard Time and is commonly abbreviated as +1245 in technical contexts.
- Which country governs the Chatham Islands' time zone?
- The Chatham Islands are part of New Zealand, and their time zone is officially managed by the New Zealand government.
- Is CHAST the same as New Zealand Standard Time?
- No, New Zealand Standard Time (NZST) is UTC+12, while CHAST is +12:45, making the Chatham Islands 45 minutes ahead of mainland New Zealand.
Source: IANA tzdb2026d · Reviewed
Free · Developer API
This time zone, as JSON.
Its defining offset, DST status and member counts, from one endpoint.
Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.
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