Go to the part where Big Ed and his wife come into Jack's house on Christmas morning. Ed says that it is 8:00 in the morning. Later, when Jack comes back into his house, his wife says that he went out at 7:30 in the morning. I don't think it took him 30 minutes to get ready to go downstairs.
I noticed that too. However, I think they did that on purpose to make it feel more real. Think about it...when someone asks us something like "What time did you leave the party?", we don't say 12:32. We say 12:30. I think it was just the actors making estimations.
Ed said it was nearly 8:00.......or before 8:00....not exactly 8....they were talking about drinking egg nog or something ...and he said ....why not it's not even 8:00 yet .....or something...