Christmas Day.

Christmas Day
The Christmas season and all its activities are geared to the big day,
Dec. 25, which is Christmas Day. The word Christmas is derived from Middle
English 'Christemasse' and Old English 'Cristes maesse,' both of which means
'Christ's Mass.' The day is celebrated by Christians as the day that Jesus
Christ was born, although the true date of Jesus' birth isn't really known.
Given the religious significance of Christmas Day, it therefore follows
that attending church is a big tradition on that day. It is seen as mandatory
for devout Christians and for others who are concerned about retaining the
sacred meaning of the day. Many people fear that the sacred aspects of Christmas
are being lost and overshadowed amid the bustle of commercial activity now
associated with the entire season.