---------- Forwarded message ---------- From: Peter Dörrie <peter.doer...@googlemail.com> Date: 2009/5/22 Subject: Re: [OSM-talk] New Proposed Feature: Tagging the age and duration of existence of features To: Lester Caine <les...@lsces.co.uk>
The problem comes with 'end_date', and since in some areas roads ARE > being destroyed, are they removed from the map or CAN they be left with > an end_date and features which have an end_date earlier than the current > date are ignored? ( I'm thinking of the 2012 Olympic site which has > re-routed many roads? ) I think that tagging a feature with end_date (or existed_till) should by default have the same effect as deleting it. It vanishes from potlach etc. But you should have an option in every editor to show features tagged with end_date. end_date would also only apply to features that at one point really did exist. Errors in the map should be deleted as usual. > > > The actual content of a date is a major point of discussion, but for the > time being I would propose sticking with a simple ISO date format. The > discussion on historic date formats has been going on for years now on > the genealogical lists without agreement. Just consider where a > start_date is between two known dates. i.e. a feature is absent on a map > of 1945 but present in the 1955 map - so you end up with a more complex > start_date entry ... and which calendar was used to provide the date ;) To keep things simple I would suggest that if you do not now the exact date, than you should interpolate. So if a feature was build somwhere between 1600 and 1650 than it is probably good to tag it with 1625. If more detailed information becomes available, you can come back to it at a later point. Also, I think that the "western" date system should apply to OSM. All other calendars can be quite easily converted. ( start_date and end_date were I think added for things like festivals > and other transitory map information, so it may be appropriate to > redefine them as constructed_date and demolished_date to distinguish > historic data from transitory data ? ) I also think that start_date and end_date are not the best description for the construction/destruction of a feature. > > > -- > 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// > Firebird - http://www.firebirdsql.org/index.php > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk >
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