December (i/dɨˈsɛmbər/ di-SEM-bər) is the twelfth and last month of the year in the Julian and Gregorian Calendars. It is one of seven months with the length of 31 days.December is the first month of meteorological winter in the Northern Hemisphere. In the Southern Hemisphere, December is the seasonal equivalent to June in the Northern hemisphere, which is the first month of summer. December is the month with the shortest daylight hours of the year in the Northern Hemisphere and the longest daylight hours of the year in the Southern Hemisphere.December starts on the same day of the week as September every year and ends on the same day of the week as April every year. In common years, April and July of the previous year start on the same day of the week as December of the current year as a common year and October of the previous year always starts on the same day of the week as December of the current year as a leap year while January of the previous years starts on the same day of the week as December of the current year as a leap year and a year immediately after that. July of the previous year ends on the same day of the week as December of the current year as a common year, February and October of the previous year end on the same day of the week as December of the current year as a leap year, and January of the previous year ends on the same day of the week as December of the current year as a leap year and a year immediately before that. December starts on the same day of the week as June of the following year in years immediately before common years and March and November of the following year in years immediately before leap years. December ends on the same day of the week as September of the following year in years immediately before common years and March and June of the following year in years immediately before leap years.