On 2021-03-24 20:13, Alan Mintz wrote:
It may be more complicated than that. The years around 1900 looks like a busy time in the history of the Cook Islands – 15 islands spread over 2.2 million sq km (850,000 sq mi) of ocean, 8.5 degrees of longitude and 13 degrees of latitude – which may not have all been in sync. More than one time zone might be necessary to correctly reflect the ground truth, though I recognize it's out of the primary scope of tzdb. If a South Pacific history buff was interested in a project ...:)
Well, the text at [http://nzetc.victoria.ac.nz/tm/scholarly/tei-KloDisc-t1-body-d18.html] seems to be a good introduction to the early history, when the London Missionary Society worked against the French influence for the acceptance as a British protectorate. They probably have used time of day as measured with sundials, local apparent or mean solar time with an uncertainty of a few minutes. More precise time, as needed for the operation of a commercial port or airport, requires either local astronomical transit observations of stars or else time signals obtained via telegraphy or radio; in the latter case, a time zone offset must be chosen, and one has been fixed in the 1952 legislation. And there certainly has been a transition period until all the inhabited islands had electricity. Michael Deckers.