Sorry for not explaining the meaning of the date. The second line of the song is "It's the 21st of December, and now they're ringing the last bells "
As fotoguzzi pointed out, the date has earned the name Gravy Day.
As for the rest of the song, I will let the individual be the judge. Personally I find it touching and thought provoking and shows a different side to Christmas, but then I like a number of Paul Kelly's songs such as "Dumb Things", "To her door", "My mothers voice", "Deeper water", "Firewood and candles" and the list goes on.
Steve