This document from the CTW archive lists season 4 starting 14 days earlier than we have listed here. What was the source for the season starting on Nov. 27? I'll consult TV Guide tomorrow, hopefully, to see what it says.
If this Wiki has had the wrong episode dates for this season, we have quite a lot of work ahead of us. Luckily, IMDb is different. As of now, there are only two season 4 episodes indicated on that site so far. I'll be able to fix those in no time.
But while we're on the subject of dates for Sesame Street episodes, this seems like the perfect opportunity to bring up something I've often wondered about. We've been very good about estimating dates based on episode numbers. Only one thing, though. Have we taken leap years into account. Because, if we failed to indicate so much as one episode that aired on the 29th of February, that would throw off the datings of every episode to come after it.
Until Guillermo chimes in on the source for the date of the premiere episode, let's not discount it right away. Sesame's document could be a) the intended air date, or b) the air date for one particular region. The date we have (again, whatever the source) may still be correct, but for a different region. Sesame Street wasn't a network show, so, like The Muppet Show (although Sesame was public television and different from syndication), it wouldn't have a strict airdate schedule like a network show. In fact, I think this is still the case, at least within the last decade or so, where Chicago might air an episode on a different date than say, New York or whatever.
Whatever the case, it would be helpful to know a) the source of the date we've been using, and b) what specifically each airdate means.
The booklet matches the season airdate with what the other documents in the set have (only season two; seasons three and five aren't found in the set). And another document on some Cliff Roberts stuff follows the airdates in the document posted above.
It appears that November 13 is correct. As Scarecroe (sort of) suggested, it might have been that a regional date was printed on the Old School: Volume 3 booklet despite that not being the case among all areas.
Of course, we could have someone with sharp memory or a recording with a given date of 11-13-72 tell us when episode 406 came out, but that's most likely not going to happen. Anyone got a time machine?