Calender month defined as the calendar-period between corresponding dates, determining legal time computation and reckoning. The term calender month denotes a calendar period from a day in one month to the corresponding day in the next month, or if no corresponding day exists, to the last day of the next month; it is the ordinary legal meaning of 'month' rather than a lunar month, and time computed by calendar months must be reckoned by reference to the calendar with months of varying lengths (including February's leap-year adjustment).