Created by: Guest, Last modification: 30 Sep 2014 (19:19 UTC) by Lester Caine

In recent years the support of the use of 'Daylight Saving' has grow conciderably, with most systems now automatically changing the clock when a transition ocures. The problem comes when looking for historic settings of clock offsets. Many people who are using a timezone setting will probably not know that when looking back before the adoption UTC in 1972, much of the history is not currently supported. IANA is the current home of the tz database following a recent problem with legal action against the original team, and most systems synchronise their data against this reference. The main problem with this source is that while there is some historic material contained in the data, and changes to a locations history from a nominal set of rules is not currently supported. There is currently no great acceptance that returning correct historic data is something that the tz database should do, and even what probably incorrect data was included is currently beeing removed! So this is an initial attempt at providing a home for pre-1972 material and a fully documented historic tz database.

As a base for this we have a couple of  publically accessible sources of location information, both of which provide a link to a post-1972 timezone identifier. So all that is required is to enhance that material with the correct pre-1972 material. Obviously for much of the world, the historic evidence may be difficult to access, having been lost over time, but a base for every location will be it's Local Mean Time (LMT) when one goes back far enough. It is the move from time determined by the sun, to a common clock controlled time for an area which may be more difficult to document, and even today there is contention between 'official' time and local variations to that.

What we need to establish initially is a way of documenting what information is currently available, and to that end we need local historians to provide material to allow both historic variations and standards as well as the ongoing local variations to the official settings.

What we need todo

Local Reference Material

Links Page from tz

Other time links

Do we need Timezones