The period of duration from the same date of one month to the same date of the next month, and thus can be 28, 29 during a leap year, 30 or 31 days long. For example the duration from 21st January to 20th February
A calendar month is one of the twelve months of the year. Winners will be selected at the end of each calendar month
A calendar month is the period from a particular date in one month to the same date in the next month, for example from April 4th to May 4th
one of the 12 months of the year, space of time measured from the end of one month to the end of the next (according to the Gregorian calendar)