Overdate, Overdating. One or more numerals on a die reworked by punches or re-engraved to change the date to a later – or correct – year. Overdating is of two kinds: to correct a punch anomaly where an incorrect punch was used (or the correct one upside down, for instance), or to extend the life of a usable die by permitting it to be retained in use and changing the date to a proper year. It is accomplished by annealing, softening the die and with the correct punch in the proper location. The depth of the punching is reason for obliterating the and for a slightly raised figure in the struck piece.

Inevitably, however, parts of the under figure still remain in the die and these are still intact (though somewhat indistinct) in all pieces struck from the restored die. It is as if the under figure sunk lower into the field and left only the fuzzy remains of the topmost portion of the previous figure overshadowed by the new figure rising higher and bolder from the surface.

A common practice in the 19th century and prior -- rarely in the 20th century but these do exist, however, as the 1922 over 21 Mercury dime. Coin dies were altered by overdating to lengthen their usable life and to conform to the requirement of striking with the current date only. In the 18th century such overdating was accomplished with simple repunching. In the 19th century the practice was more of filling, CHASING and then repunching which tends to obliterate any under figures.

Each such overdate creates a new die variety. These are eagerly studied by numismatists.

Overdates are rare on medals; although medal dies are updated by die retooling – generally an annealing of the die, removal of old dates, punching or engraving the new date, then hardening of the die again. Medals do not require to be dated in the year in which they are struck – or even dated at all – but some dies are updated, say, for an annual award medal each year.

See DIE RETOOLING; DIE VARIETY; PUNCH, PUNCHEON (1); REPUNCH, EPUNCHING; UPDATE, UPDATING

References: NE42 {1982} Doty, p 240-242

NM19 {1991} Margolis, p 165-170.