Timezone details
- Identifier
- Abbreviation
- —
- Transitioned
- March 2, 1991 at 11:30 PM
- Featured city
- Avarua
Pacific • Rarotonga
Cook IslandsCurrent local time
18:58:03
Saturday, May 30, 2026
UTC offset
UTC-10:00
Rarotonga does not observe daylight saving time. Clocks stay on UTC-10:00 all year long.
Cook Islands Standard Time (CIST)
CIST is a single‑zone region at a steady UTC‑10:00. Rarotonga sits in a calm, year‑round offset with no daylight saving, making it easy to coordinate with a small‑step offset toward the Asia side of the Pacific.
Very. Most codes cover multiple members; CIST is essentially a solo zone, simplifying all comparisons and scheduling for Rarotonga.
Roughly central in the Pacific, sitting well east of Samoa Time but far west of Hawaii, creating common shorthand like 'halfway across the Pacific'.
simplified in 1991, and remained steady since, minor adjustments after minor historical adjustments
Very small landmass and tourism industry are small enough that clocks remain constant.
With a steady 10 hours behind UTC and reliable systems or Asia (+ small time difference)
Simplicity and avoided date line issues.
Often used as a reference for 'halfway across the Pacific'
It is stable now.