date mark1
/ˈdeɪt mɑːk/noun
A mark indicating the date; specifically a mark stamped or engraved on gold or silver plate, pottery, etc., denoting the year of manufacture or registration.
Origin
Mid 19th century. From date + mark. Compare earlier date stamp.
date-mark2
/ˈdeɪtmɑːk/verb
[with object] Chiefly in pass. To mark with a date.
Origin
Late 19th century; earliest use found in The Times. From date mark.