How to include the time dimension in MapML

We have to thing on how we can express a time slider in MapML. I suppose, it is part of the “controls” that can be activated or not. But, as soon as there is time involved, we need “time” in the URL template of tiles, so it need a new “input” describing the time dimension of the tiles:

So we should add “time” as one of the input @ axis values.

We did a prototype of a “time slider” which is not a slider, but allows the user to query the map at a time, using the <select name="date"><option value="1,7,14,57,22">1867</option>...</select> construct. I suppose it could also use (discrete) times and dates in the value attribute (the list of numbers in the value attribute are the layer identifiers from a WMS service that taken together compose the layer at the year indicated in the the <option>1867</option>:

I think this could be a catch-all for “queryable maps”. So long as the server populates the controls appropriately, a reasonable map should appear. It could be animated with scripting.