In case you haven't noticed, with the past several retro schedules recently posted, I have stated which episode of Sesame Street aired that day. I know that people have done it before with some of the very early episodes, but I actually know most of the airdates. And here's how I've figured it out:
From 1969 to 1998, Sesame Street produced 130 episodes each season, except for Season 2 when they produced 145, which explains the discrepancy of all the season premiere episode numbers from Season 3 onward (276, 406, 536, etc). I'm not positive as to why there were more episodes produced in Season 2, but I think it was because they weren't sure exactly how long it would take to air all the episodes, or maybe some of them were even just given new production numbers (I've heard of that happening with syndicated shows when they reran). It is well known that the show premiered on Nov. 10, 1969, but on the SS Old School Vol. 1 and 2 sets, it lists the dates for all the season premieres (1-10). They picked 130 episodes per season because it would take exactly 26 weeks to air them, which is exactly half the year. And for the other half, they would rerun the entire season. For most of the show's run, the season started in November and ended in May. But throughout the entire season, there was a new episode scheduled to air for each and every weekday (including major holidays such as Thanksgiving and Christmas). Here is a list of all the air dates for each season:
Season 1 (Episodes 1-130): 11/10/69 - 5/8/70
Season 2 (131-275): 11/9/70 - 5/28/71
Season 3 (276-405): 11/8/71 - 5/5/72
And then:
Season 4 (406-535): 11/27/72 - 5/25/73
Season 5 (536-665): 11/19/73 - 5/17/74
Season 6 (666-795): 11/4/74 - 5/2/75
So it seems like for the first 3 seasons, the schedule was pretty consistent, but in Season 4 they started toying around with the season premiere date. However, from Season 7 to Season 24, it was pretty steady:
Season 7 (796-925): 12/1/75 - 5/28/76
Season 8 (926-1055): 11/29/76 - 5/27/77
Season 9 (1056-1185): 11/28/77 - 5/26/78
Season 10 (1186-1315): 11/27/78 - 5/25/79
Season 11 (1316-1445): 11/26/79 - 5/23/80
Season 12 (1446-1575): 11/24/80 - 5/22/81
Season 13 (1576-1705): 11/23/81 - 5/21/82
Season 14 (1706-1835): 11/22/82 - 5/20/83
Season 15 (1836-1965): 11/21/83 - 5/18/84
Season 16 (1966-2095): 11/19/84 - 5/17/85
Season 17 (2096-2225): 11/18/85 - 5/16/86
Season 18 (2226-2355): 11/17/86 - 5/15/87
Season 19 (2356-2485): 11/16/87 - 5/13/88
Season 20 (2486-2615): 11/14/88 - 5/12/89
Season 21 (2616-2745): 11/13/89 - 5/11/90
Season 22 (2746-2875): 11/12/90 - 5/10/91
Season 23 (2876-3005): 11/11/91 - 5/8/92
Season 24 (3006-3135): 11/9/92 - 5/7/93
So from Season 7 through 24, it was pretty consistent, but for some reason in between the last airing of 3135 and the Season 25 premiere (3136), they reran 3006-3015, so those episodes got shown 3 times. I'm guessing it was because they realized that the season premiere date kept getting earlier and earlier as time went on, so they adjusted it.
Season 25 (3136-3265): 11/22/93 - 5/20/94
Season 26 (3266-3395): 11/21/94 - 5/19/95
Season 27 (3396-3525): 11/20/95 - 5/17/96
Season 28 (3526-3655): 11/18/96 - 5/16/97
Season 29 (3656-3785): 11/17/97 - 5/15/98
And that is what I call the end of the "Classic" Sesame Street era. Airdates were consistent for the most part, but they would usually flip-flop the 3rd week in August and either the first or second week in September so that they could air the special "pledge edited" shows during their pledge drive in August. For most PBS stations, pledge month was always March, and so the episodes that would usually be airing around that time would have special edited versions with a few individual segments cut out.
Starting in Season 30, the show really started going down hill. It was the debut of the dreaded Elmo's World, but it was also when they cut the number of episodes per season in half, and the schedule started getting more inconsistent. Starting in Season 30, only 65 shows were produced each season for 3 seasons. In Season 33, they produced 50 shows, and ever since then, they only produce 26 new episodes per season. That may sound like a random number of episodes, but they chose that number (26) for a reason. If they were to only do 25 episodes per season, they would have to ask the question, "What letter of the alphabet do you wanna fire?"
The past few seasons (41 and 42), they did have what they call "revised reruns" with new episode numbers, sometimes with new wraparounds, but not always. In both seasons, there were 44 episodes altogether (including the reruns).
From 1969 to 1998, Sesame Street produced 130 episodes each season, except for Season 2 when they produced 145, which explains the discrepancy of all the season premiere episode numbers from Season 3 onward (276, 406, 536, etc). I'm not positive as to why there were more episodes produced in Season 2, but I think it was because they weren't sure exactly how long it would take to air all the episodes, or maybe some of them were even just given new production numbers (I've heard of that happening with syndicated shows when they reran). It is well known that the show premiered on Nov. 10, 1969, but on the SS Old School Vol. 1 and 2 sets, it lists the dates for all the season premieres (1-10). They picked 130 episodes per season because it would take exactly 26 weeks to air them, which is exactly half the year. And for the other half, they would rerun the entire season. For most of the show's run, the season started in November and ended in May. But throughout the entire season, there was a new episode scheduled to air for each and every weekday (including major holidays such as Thanksgiving and Christmas). Here is a list of all the air dates for each season:
Season 1 (Episodes 1-130): 11/10/69 - 5/8/70
Season 2 (131-275): 11/9/70 - 5/28/71
Season 3 (276-405): 11/8/71 - 5/5/72
And then:
Season 4 (406-535): 11/27/72 - 5/25/73
Season 5 (536-665): 11/19/73 - 5/17/74
Season 6 (666-795): 11/4/74 - 5/2/75
So it seems like for the first 3 seasons, the schedule was pretty consistent, but in Season 4 they started toying around with the season premiere date. However, from Season 7 to Season 24, it was pretty steady:
Season 7 (796-925): 12/1/75 - 5/28/76
Season 8 (926-1055): 11/29/76 - 5/27/77
Season 9 (1056-1185): 11/28/77 - 5/26/78
Season 10 (1186-1315): 11/27/78 - 5/25/79
Season 11 (1316-1445): 11/26/79 - 5/23/80
Season 12 (1446-1575): 11/24/80 - 5/22/81
Season 13 (1576-1705): 11/23/81 - 5/21/82
Season 14 (1706-1835): 11/22/82 - 5/20/83
Season 15 (1836-1965): 11/21/83 - 5/18/84
Season 16 (1966-2095): 11/19/84 - 5/17/85
Season 17 (2096-2225): 11/18/85 - 5/16/86
Season 18 (2226-2355): 11/17/86 - 5/15/87
Season 19 (2356-2485): 11/16/87 - 5/13/88
Season 20 (2486-2615): 11/14/88 - 5/12/89
Season 21 (2616-2745): 11/13/89 - 5/11/90
Season 22 (2746-2875): 11/12/90 - 5/10/91
Season 23 (2876-3005): 11/11/91 - 5/8/92
Season 24 (3006-3135): 11/9/92 - 5/7/93
So from Season 7 through 24, it was pretty consistent, but for some reason in between the last airing of 3135 and the Season 25 premiere (3136), they reran 3006-3015, so those episodes got shown 3 times. I'm guessing it was because they realized that the season premiere date kept getting earlier and earlier as time went on, so they adjusted it.
Season 25 (3136-3265): 11/22/93 - 5/20/94
Season 26 (3266-3395): 11/21/94 - 5/19/95
Season 27 (3396-3525): 11/20/95 - 5/17/96
Season 28 (3526-3655): 11/18/96 - 5/16/97
Season 29 (3656-3785): 11/17/97 - 5/15/98
And that is what I call the end of the "Classic" Sesame Street era. Airdates were consistent for the most part, but they would usually flip-flop the 3rd week in August and either the first or second week in September so that they could air the special "pledge edited" shows during their pledge drive in August. For most PBS stations, pledge month was always March, and so the episodes that would usually be airing around that time would have special edited versions with a few individual segments cut out.
Starting in Season 30, the show really started going down hill. It was the debut of the dreaded Elmo's World, but it was also when they cut the number of episodes per season in half, and the schedule started getting more inconsistent. Starting in Season 30, only 65 shows were produced each season for 3 seasons. In Season 33, they produced 50 shows, and ever since then, they only produce 26 new episodes per season. That may sound like a random number of episodes, but they chose that number (26) for a reason. If they were to only do 25 episodes per season, they would have to ask the question, "What letter of the alphabet do you wanna fire?"
The past few seasons (41 and 42), they did have what they call "revised reruns" with new episode numbers, sometimes with new wraparounds, but not always. In both seasons, there were 44 episodes altogether (including the reruns).