Originally Posted by wayman
You noted it is unlikely they filmed that close after the New Year's holiday. I also question the filming date of the pilot as 12/26/1975, the day after Christmas.
Maybe I should have worded this differently - I should have added that 1/6/1977 was probably not a possible filming date for the Birthday/Anniversary Show since I don't see any real way that they can air something just four days after producing it, even though a good half of it was a flashback episode and used scenes previously filmed (and mostly aired). Especially since the smallest gap between production date and airing date was 18 days, and many of them have that gap at usually one month or so.