Useful enhancement to functions involving calendar dates
I just finished reviewing a batch of military records in which the date at the top read--
February (hole punch destroyed the day) 1922.
The indexer assumed (probably correctly with these particular records) that the obliterated date was the last day of the month. So far so good. Unfortunately, they listed all the dates as February 31, 1922. 1922 was not a "presidential" year, so the 28th was the last day of February that year. The indexer did excellent work otherwise in the entries; didn't find any other errors. But I suggest it would be a good idea if you added some additional functionality to the program so it won't let indexers enter a nonexistent date. In this case when an indexer entered Feb in the first cell, 31 in the second, and 1922 in the third, they'd get an error message: "Non-valid date" or something like that.