calendar month

plural calendar months

1. The period of duration from the first date of one month to the last date of the same month, which can thus vary from 28 to 31 days in length.

   1 more example

   In Calcutta, season tickets are issued only for the calendar month, with a different colour for each month, so that this problem does not arise. The merest whisper of an idea to change Bombay to the Calcutta system brought such a howl of protest in the Press, that it was never seriously contemplated.

   1953 November, 'Erca', “Ticket Frauds in the East”, in Railway Magazine, page 779