The calendar year starts on 1st January – but for the Church its New Year starts on Advent Sunday (the fourth Sunday before Christmas).The actual date varies but it is usually the last Sunday in November or the first Sunday in December.
Advent comes from the Latin word Adventus, which means coming, and it’s the time when the Church gets ready for the birth of Jesus, celebrated at Christmas.
In Roman times purple cloth was the most costly, and was associated with kings and rulers. And so the colour for Advent, the getting ready for King Jesus, is purple.
Advent in 2 minute https://www.youtube.com/watch?feature=player_embedded&v=S02KOlw7dlA#!
What is Advent? http://projectbritain.com/Advent.html