April 5 Al-Hijra (New Year's Day) Muslim: Marks the point at which Muhammad succeeded in spreading Islam beyond Mecca to Medina. This "migration" - Hijrah - is used as the start of the Muslim calendar.
April 14 Vaisakhi (Baisakhi) Sikh: The main festival and the beginning of the Sikh year, Baisakhi commemorates the occasion in 1699 (CE) when Guru Gobind Singh called upon Sikhs for loyalty and to express their belief by their adoption of the "Five Ks" and the use of the name Singh for men and Kaur for women.
April 20-27 Passover (Pesach) Jewish: Commemorates the Exodus of the children of Israel from slavery in Egypt - and draws attention to the continuing quest for liberty across the world. The central focus is the Passover meal, filld with the symbolism of bitterness and redemption.
April 16-23 Easter Christian: A series of days marks the progress of Jesus towards his resurrection on Easter day, culminating in Palm Sunday (April 16) with processions and the giving of palm crosses marking the entry of Jesus into Jerusalem.
April 20, Maundy Thursday Remembers the day that Jesus told his disciples to perform the Eucharist in remembrance of him.
April 21, Good Friday The day of the Crucifixion.
April 23, Easter Day The day of the Resurrection of Jesus on the third day after his death on the cross.
April 23 St George's Day St George is the patron saint of England. We know little of the real George, but he probably existed, perhaps as a Middle Eastern soldier in the Roman Army, tortured and killed for his Christian beliefs. The legend of his fight with the dragon to save a damsel being sacrificed came later, but was already popular in the Middle Ages.