April (Lat. Aprilis), the 4th month of the year, consisting of 30 days. With the Romans it was the 2d month of the year. Julius Caesar added the 30th day to it. In the time of Nero it was called Neroneus. The name is supposed to be derived from aperire, to open, because the buds open themselves at this period. In the Athenian calendar, the latter portion of Elaphebolion and the greater part of Muny-chion correspond to April. Charlemagne, in his new calendar, called it grass month, the name still given to it by the Dutch (grasmaand). The French revolutionary calendar merged it into the greater portion of Germinal and the commencement of Floreal. On antique monuments Aprilis is represented as a dancing youth with a rattle in his hand. - The custom of sending people on empty errands on the 1st of April (hence called All Fools' Day) is common in every country of Europe. Oriental scholars say that it is derived from the hull feast among the Hindoos, where a similar custom prevails. Another opinion is that it comes from a celebration of Christ's being sent about to and fro between Herod, Pilate, and Caiaphas. In France the fooled man is called poisson d'avril, meaning a silly fish, easily caught.
In Scotland he is called gowk, which means a cuckoo.