I’m wondering if there is any interested by OSM in holding Timezone boundaries by creating a new boundary type for them.
Eric Muller has created the shapes at:
http://efele.net/maps/tz/world/
If we had the boundaries he made imported in OSM, people could contribute to modify them and make them more accurate.
Any thoughts would be appreciated.
This was recently discussed in the US-mailing list: https://lists.openstreetmap.org/pipermail/talk-us/2016-May/016331.html
My interpretation of the discussion is that it should be kept outside of OSM.
Most timezone boundaries correspond to administrative boundaries, so importing them as separate shape files would be wrong. They would need to share nodes with the existing boundaries, or be created as relations based on existing areas.