When I was younger and lived at home, the Christmas tree typically went up around my late mother's birthday, which was the 6th - so usually, the first or maybe second Sunday of December. It then took pride of place in the front room, sometimes in the bay window until a few days after Twelfth Night, so it was up for the date my late father would have celebrated Christmas (he was Ukrainian).
Lights were the old-fashioned moulded glass ones where if one bulb failed, they all went out: a string of twelve. Nowadays if you want to find an original set of those, expect to pay good money.