One of the joys of running a slightly unorthodox campaign with a central “big mystery” is that certain aspects of the game world are bound to include subject matter not normally covered by the rules as written. It is those cases that really make the campaign your own, regardless of whether you’re running a completely homebrewed campaign world or one which came in a box.
The following spell is probably of little value to many typical campaigns, but for those of the same peculiar frame of mind as my own (or for those who have a similar oddball referee); this minor piece of magic might be found useful.
Know Age (Magic-user and Elf spell)
Duration: 1 round per level
Upon completing this incantation, the caster intuitively knows the age of any object or creature touched with a ± 1 year margin of error. Living beings are allowed a save vs. spells should they wish to conceal their age.