Nothing supports any of these, but there are several suggested approaches:

  1. bicycle:times=Mo-Fr 17:30-09:00; Sa-Su 24h
    pro: format is the same as Key:opening_hours
    con: doesn’t work if it should be bicycle=destination at those times. Although it could be added to the end of the time intervals.

  2. a access relation
    one member, the pedestrian highway (or several, if it’s split for other reasons)
    relation tags:
    type=access
    vehicles=bicycle
    bicycle=yes
    times=Mo-Fr 17:30-09:00; Sa-Su 24h

  3. including the time in the key part
    bicycle:[Mo-Fr 17:30-09:00; Sa-Su 24h]=yes
    cons: unusable with current tools that mostly rely on having one key for one property.

Any of these should be comprehensible to someone later manually converting the values to a scheme implemented somewhere at that time.