From The Art and Popular Culture Encyclopedia
April is commonly associated with the season of spring in the Northern hemisphere and autumn in the Southern hemisphere, where it is the seasonal equivalent to October in the Northern hemisphere and vice versa.
April starts on the same day of the week as July in all years, and January in leap years. April ends on the same day of the week as December every year.
April was the second month of the Roman calendar, before January and February 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 derivation of the name (Latin Aprilis) is uncertain. The traditional etymology is from the Latin 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 ἁνοιξις (anoixis) (opening) for spring. Since some of the Roman months were named in honor of divinities, and as April was sacred to the goddess Venus, the Festum Veneris et Fortunae Virilis 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.