Zechariah spent nine months pondering what the angel had said to him. It was nine months of anticipation. It was nine months of advent. Why? Surely this old priest was slightly distracted by the news that his elderly wife was going to have a son? Of course. But he knew the implications of the message from the messenger, and the message of Malachi.
If his son was going to be the one to prepare the way, then that meant that his Lord would be following soon after and coming to His temple. We read the Zechariah story as if it is a mildly interesting prelude to the more familiar birth of Christ. He lived it as if it was the most exciting preparation for the greatest of births.