Paul Eggert wrote:
Guy Harris wrote:
If we're obliged to leave them in the tzdb for backwards compatibility purposes, we should: accompany them with a disclaimer that they're not actually meaningful
That sounds reasonable. Here's a draft of a disclaimer, along with a pointer to a discussion of how little we know even about solar time if we go back far enough, and if it weren't for those amazing Babylonian astronomers we'd know even less. I've pushed this into the experimental repository.
Paul - I still object to using 1970 as some magic point at which data came good! Just because some legacy systems can't cope with 'negative times' is not a good basis. Yes some material needs to be tagged with a level of uncertainty, and when putting genealogical timestamps that is normally the case, but much of the pre-1970 TIME ZONE information IS accurate? Even after 1970 there is a level of inaccuracy - mainly political? - so its almost a case of providing a flag when something is disputed? I do like this particular change but in does only need to be an agreed standard for taking location information and creating a time offset? The 'equation' can then be used with any location just by feeding the coordinates in, so there is no need for a 'database'. In fact, any existing 'location' in the database we should be able to access TZ offset, and LMT offset as both have a purpose. When someone says 'an hour after midday' the two times may well provide insite to some discrepancy! -- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk Rainbow Digital Media - http://rainbowdigitalmedia.co.uk