Is there a way of storing an historic date for which the exact date is unknown?
There are three broad categories that make up unknowns.
The obvious one is an unknown day/month that something occurred, such as "in 1782...." or perhaps narrowing it down "in March 1843...."
The current solution is to set the date to 1 January 1782 or 1 March 1843, which isn't wholly satisfactory.
The next unknown is when something happens by. In other words, the exact day, month, and year are and remain unknown, but there comes a point when these things do become known to have happened by. So it could be that "Bob moved to New York by 1966..." or that "By June 1903...." when the event in question really happened months or years beforehand.
Finally there's circa, as in "the church was built circa 1860".
The problem is that date fields demand exactitude when sometimes historic events get lost in time.
Unless this has already been covered (in which case I've missed it), perhaps a logical solution would be to be able to replace days or months with UU, BB, and CC ...?