datemark

plural datemarks

1. A marking that indicates a date.

   It ends with a datemark (8 April 628), a note that the army was striking camp and setting off on the march home, and a request for prayers for their safe return (734. 13–17).

   2010, James Howard-Johnston, Witnesses to a World Crisis, page 49

   1 more example

   Again, some light on those great datemarks, the migrations to America, ought to be derivable from studies of the indispensable conditions for crossing the Pacific, and particularly the stages of development of navigation.

   1916, Proceedings of the Royal Society of Canada, page 479