Moving mm/dd/yyyy into separate fields -- not solved yet
Spoke too soon. Using TSGal's method, what happened is this:
Any mm/dd/yyyy Date textfield entry that was complete by Date field standards -- that is with a day date, a month date, and a year -- did get moved, although with 01 changed to 1, etc., in both the month and day fields.
For any entry in which either the date or the month was set at 00/, the three separate fields now contain question marks -- even if the month and year were included in the entry.