[LEAPSECS] Calendrical Calculations

[Tony Finch]

On Sun, 28 Dec 2008, Zefram wrote:

>

> The numerical algorithms are correct, as far as I can see, but the

> descriptions of the underlying theory are often muddled, riddled with

> errors and critical omissions. (Count how many different quantities go

> by the name "RD".)  Rather importantly for our purposes, CC ignores the

> existence of timezones (or, for that matter, longitude).


A lot of the book is only concerned with labelling days, so it's a
legitimate simplification to ignore time of day. However they do take some
care to explain the simplification and how it relates to the way different
calendars choose different times of day to change their dates.

The rest of the book is concerned with modelling observational calendars,
and for those it does require a more detailed idea of time of day and
location, including longitude. There is also a brief discussion of time
zones, which are mostly used when converting civil time at a place to
universal time for use by the algorithms.

Tony.
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