Definition of calendar month

The term "calendar month" refers to the standard length of a month in the modern Gregorian calendar used in many countries today. This calculation takes into account the fact that months vary in length, ranging from 28 to 31 days, and includes extra days in years with leap years (every four years) to synchronize it with the solar year of about 365.25 days. However, when creating calendars for practical purposes, a more uniform and predictable monthly length is required for administrative, legal, and commercial purposes. To address this need, the term "calendar month" was coined as a precise measure of time equal to 30.4 days on average. It allows for easy and consistent calculation of deadlines, rent payments, contractual obligations, and other time-bound affairs in which exact dates are required, regardless of the number of days in the particular month. In summary, "calendar month" is a term commonly used in legal, financial, and business contexts to denote a fixed period of time, typically 30 days, for the convenience of computation and administration, in contrast to the varying lengths of lunar or ordinary months.