[tz] scope of tz database, scholarship

Lester Caine lester at lsces.co.uk
Sun Sep 1 21:55:25 UTC 2013

Steve Allen wrote:
> In addition to that, for all practical purposes, civil time prior to
> 1972 did not use SI seconds, but rather mean solar seconds, and
> for dates prior to 1955 there cannot even be an argument.
> Therefore in the extended range of the tz database there is an
> arguably unspecified point when the kind of seconds counted changes
> from mean solar (UT) to atomic (SI).

The recent sample scripts were based on 'seconds', but personally all of my data 
is stored in a database powered by Firebird. This uses a 32 bit number for the 
'date' and a 32 bit fraction for the 'part of a day' ... neatly sidesteps the 
leapsecond problem but is a bugger when you need DST :) Which is why we store 
everything in UTC and the TZ data is so critical to display 'local' time!

Lester Caine - G8HFL
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