How to tag future public transport lines

Where I live there are plans to change the numbering of public transport lines (esp. busses) as well as the routes of the lines. So at date x the current lines and line-numbering becomes invalid and new routes and line-numbers are in place.

How can I create the required new routes today and tag them so that they are only effective from day x on?

And how do I tag the current lines to make clear that they are not to be used after day x?

Thanks for your help!

Unless you have the proper database rights on the list of new route numbers, you simply may not be allowed to do this and will have to re-survey on the ground.

However, if you selectively extract the relations from OSM into a file, you can then save them into a file and edit them at your leisure using JOSM, occasionally doing updates to merge in any third party changes, and finally upload the result when the change becomes official.

Thanks hadw. But I was more thinking about something like a

since

or

until

-tag for a line that show when the line will become active or inactive. Something like the tags mentioned in http://wiki.openstreetmap.org/wiki/Comparison_of_life_cycle_concepts or http://wiki.openstreetmap.org/wiki/Proposed_Features/Life_cycle_relation - But both are - at least as far as I understood them - for actual buildings and not for more virtual relations like bus lines.

We already have a start_date tag to indicate when something “comes into existence”.
The tag end_date is already used 15.000 times and is likely to indicate “until”

I started under the presumption that it is basically only the route numbers that are changing, in which case you do not want to create any new relations, which is what you would need to add a start date.