Merry Christmas!

Recently, I have been receiving a lot of Christmas e-cards which cajole the recipients to celebrate the birthday of Jesus Christ.

But of course, Jesus was not really born on December 25. In fact, no one really knows when Jesus was born, or when he died. These 2 holidays that we mark on our calendars were decreed by the Catholic Church. Good Friday was formalised in the year 325 AD, and Christmas some time in the late 300s (probably 378 AD).

Think about it: Good Friday is celebrated on 21 March 2008 this year. However, it will be celebrated on a different date, 10 April 2009, next year. Why is Good Friday - Jesus death anniversary - not commemorated on a fixed day, but Jesus birthday is? (Note: Good Friday always fluctuate between March 21 and April 23 inclusive.)

If Jesus death anniversary can fluctuate every year, shouldn't Jesus birthday fluctuate every year as well?

The reason why Good Friday fluctuates is because the Hebrew calendar is actually based on the Moon, whereas our current calendar - derived from the Romans - is based on the Sun. As Good Friday is actually determined by the Hebrew calendar, this is the reason why the date fluctuates when mapped onto our solar calendar.

Logically speaking, Jesus birthday should follow the Hebrew calendar too, and thus Jesus birthday should fluctuate when mapped onto our solar calendar. For consistency with the fluctuating Good Friday, Jesus birthday should not be celebrated on a fixed December 25 every year, but should fluctuate likewise.

The bible does not explicitly state the date of Jesus birth. So why was Jesus birthday fixed on December 25?

One explanation is that the early Christians, being Jews, believe that their prophets always die on an anniversary of their birth, or of their conception. For Jesus, it was believed that his death on Good Friday was on the anniversary of his conception. If Jesus was conceived in March/April, then his birth, 9 months later, would be some time in either December or January.

During ancient times, people living in temperate countries have noticed that there is a day in the 3rd week of December where the hours of daylight is the shortest in the year (typically December 21 or December 22). This astronomical event is called the Winter Solstice. The Winter Solstice is commemorated by many ancient civilisations, including China.

In Rome, the common people have been celebrating the week long festivities of the Winter Solstice as Sol Invictus, or "the birthday of the unconquered Sun". This holiday has been celebrated for hundreds of years, where prayers and offerings are made to various Sun gods like "Elah-Gabal", "Sol", and "Mithras".

When Rome adopted Christianity as its official and ONLY religion, it could not rid its people from their pagan celebrations and worship of the sun gods during the Solstice festivities. The Catholic Church thus decided to co-opt the "birthday of the Sun" to the "birthday of the Son". The festivities were now made into the worship of Jesus instead of the worship of Mithras et al.

In Jewish families, infant boys must be circumcised on the eighth day of their birth, in a ritual known as the Brit Milah, to honour the covenant between Yahweh and the Children of Israel. Since Jesus is a Jew, he would be circumcised on his 8th day, and that would be the first day the child is officially with God. It was conveniently proposed that Jesus was circumcised on January 1, which means that he must have been born 8 days prior, on December 25, to coincide with the Solstice festivities.

And that is how Jesus birthday became officially fixed on December 25, and which we now mark on our calendars as Christ's Mass day.

Merry Christmas!