Just thinking of this, it reminds me of the old postmark ledger we used to keep when I worked at
Canada Post. We had a manual hammer that the date had to be changed in everyday. There were blank forms, much like what you describe, with empty boxes approximately 2"x2" in size. After you changed the date on the hammer, you were supposed to ink it and make an impression in the next empty box, and then visually check the results to make sure the type was in rightside up, etc.
Sometimes it's fun to be cursed with a long memory...