(N) :
A key date is a term used in coin collecting and it refers to a date (or date and mint mark combination) of a given coin series or coin set that is harder to obtain than other dates in the series.
(N) :
A key date is a term used in coin collecting and it refers to a date (or date and mint mark combination) of a given coin series or coin set that is harder to obtain than other dates in the series.