The Calendar Month of April

April is the fourth month of the year in the Gregorian calendar, the fifth in the early Julian calendar, and the first of four months to have a length of 30 days. April is commonly associated with spring in parts of the Northern Hemisphere and autumn in parts of the Southern Hemisphere. It is the seasonal equivalent to October in the Northern Hemisphere and vice versa.

April was originally the second month of the ancient Roman calendar before January and February were added by King Numa Pompilius about 700 BCE. It became the fourth month of the calendar year (when they show the twelve months) during the time of the decemvirs about 450 BCE when it also was given 29 days. They added the 30th day during the reformat of the calendar undertaken by Julius Caesar in 45 BCE, which produced the Julian calendar.