tzdata rule group

Cook

Historical rule context · 1 represented zone

A rule group describes recurring clock changes. It is not itself a place or an IANA time-zone identifier.

First rule
1978
Last rule
1991
Rule entries
3
Source files
australasia

Notes from the time database

Context for this rule

These source notes are preserved from tzdata. They help explain a rule’s period, without adding claims beyond the source.

1978–1991

Rule context

Cook Is In 1899 the Cook Islands celebrated Christmas twice to correct the calendar. According to the old books, missionaries were unaware of the International Date line, when they came from Sydney. Thus the Cook Islands were one day ahead.... ... Appendix to the Journals of the House of Representatives, 1900 (page 20) ... in the Cook Island Act of 1915-10-11, online at "651. The hour of the day shall in each of the islands included in the Cook Islands be determined in accordance with the meridian of that island." so that local (mean?) time was still used in Rarotonga (and Niue) in 1915. This was changed in the Cook Island Amendment Act of 1952-10-16 ... "651 (1) The hour of the day in each of the islands included in the Cook Islands, other than Niue, shall be determined as if each island were situated on the meridian one hundred and fifty-seven degrees thirty minutes West of Greenwich. (2) The hour of the day in the Island of Niue shall be determined as if that island were situated on the meridian one hundred and seventy degrees West of Greenwich." This act does not state when it takes effect, so one has to assume it applies since 1952-10-16. But there is the possibility that the act just legalized prior existing practice, as we had seen with the Guernsey law of 1913-06-18 for the switch in 1909-04-19. Transitions after 1952 are from Shanks & Pottenger.

Original rule fields

Recorded rule entries

Structured directly from tzdata’s Rule lines.

FromToTypeInOnAtSave
1978only-Nov120:000:30
19791991-MarSun>=10:000
19791990-OctlastSun0:000:30