*Regular: A "regular" date is one which includes an interval spanning a specific day, month, or year. It can be complete (or 'fully qualified' for a 24 hour interval like June 6, 1990) or partial (like omitting the day for a 1 month interval like July 1977 or omitting the day and month for a 1 year interval).
*Before: A "before"
(date is one that can only be identified as occurring (in a preferences-defined long interval) prior to a certain day, month, or year.
*After: An "after" date is one that occurs (in a 2nd preferences-defined long interval) following a certain day, month, or year.