Mental Floss

Brain Game: The Monthlies


It may take you days to solve today's Brain Game. In fact, I guarantee that it will, because it's about calendars. Suppose you're a craftsman that likes to print calendars using wooden blocks. You've designed a grid exactly like this one:

calendar /

How many different blocks would you have to carve to fit inside the above grid to handle ALL possible months?

Here is the SOLUTION.


FORTY in all. The calendar would require:

  • 31 blocks for the numbers 1 through 31
  • 2 "split date" blocks reading "23/30" and "24/31" (for 31-day months beginning on Friday, or 30- or 31-day months beginning on Saturday, see sample below)
  • 7 "blank" blocks (all would be used in a non-leap-year February)
August 2009 sample
August 2009 sample /