Whitsun

Today is Whitsun, which is short for Whit Sunday. The pronunciation is /ˈwɪtsən/ or /ˈhwɪtsən/. It's the seventh Sunday after Easter, observed as a festival of the Christian Church commemorating the descent of the Holy Spirit on the day of Pentecost. In Old English times it was called Hwíta Sunnandæg, i.e. White Sunday. In the Anglo-Saxon Chronicle we find a section describing that Matilda, wife of William the Conqueror, was consecrated queen at Westminster in the 11th c.: "hig [= Matilda] gehalgode to cwene on Westmynstre on Hwitan Sunnandæg."

Why 'White'? It seems to refer to the old custom of wearing white robes by persons to be baptised.
This day was and is an occasion for varied forms of celebration:

Whitsun Ales was a parish celebration held originally to raise money for church fund
Parades with brass bands and choirs
Morris dancing, which seemed to have originated as court dancing in the Middle Ages
AHEM!