Puzzle No. 025

This one is by Mr. Puzzle himself, Martin Gardner (and man, this is though).

Build a calendar from two sets of cubes. On the first set, spell the months with a letter on each face of three cubes. Use lowercase three-letter English abbreviations for the names of all twelve months (e.g., "jan", "feb", "mar"). On the second set, number the days with a digit on each face of two cubes (e.g., "01", "02", etc.).

Source: M. Gardner