April is the fourth month of the year in the Gregorian calendar , the fifth in the early Julian, the first of four months to have a length of 30 days, and the second of five months to have a length of less than 31 days.
April is commonly associated with the season of autumn in parts of the Southern Hemisphere, and spring in parts of the Northern Hemisphere , where it is the seasonal equivalent to October in the Southern Hemisphere and vice versa.
The Romans gave this month the Latin name Aprilis but the derivation of this name is uncertain. The traditional etymology is from the verb aperire, "to open", in allusion to its being the season when trees and flowers begin to "open", which is supported by comparison with the modern Greek use of άνοιξη (ánixi) (opening) for spring . Since some of the Roman months were named in honor of divinities, and as April was sacred to the goddess Venus , her Veneralia being held on the first day , it has been suggested that Aprilis was originally her month Aphrilis, from her equivalent Greek goddess name Aphrodite (Aphros), or from the Etruscan name Apru. Jacob Grimm suggests the name of a hypothetical god or hero , Aper or Aprus.April was the second month of the earliest Roman calendar , before Ianuarius and Februarius were added by King Numa Pompilius about 700 BC. It became the fourth month of the calendar year (the year when twelve months are displayed in order) during the time of the decemvirs about 450 BC, when it also was given 29 days. The 30th day was added during the reform of the calendar undertaken by Julius Caesar in the mid-40s BC, which produced the Julian calendar .
The Anglo-Saxons called April ēastre-monaþ. The Venerable Bede says in The Reckoning of Time that this month ēastre is the root of the word Easter . He further states that the month was named after a goddess Eostre whose feast was in that month .