When an object is saved in OSM, the changeset ID is saved with it, and the changeset includes its own metadata in the form of both automatically entered attributes (the user, the date), and also its own set of tags.
The problem with specifying a date in the form you mentioned are a few: 1) All data is already implied to be as of the date entered into the DB. 2) Data that's not individually surveyed (ie is from an import) should already store some metadata about its collection 3) This doesn't solve the timeline proble, 1 and 2 seem self-explanatory (and if that's not the case, let me know and I'll elaborate). The problem is 3: You may say (as you do) that a park is empty at some point and then a playground is entered. But for this to be useful, we'd have to assume that you've surveyed the entire park and have entered everything in the park. You might think you've entered everything, but then I'll come around and enter in the water fountains, portable toilets and waste bins. So does that mean these objects didn't exist when you were there and were added later? Then we're back where we are now, not knowing if this is a new feature, or simply one that's not been entered into the system. - Serge _______________________________________________ newbies mailing list [email protected] http://lists.openstreetmap.org/listinfo/newbies
