why did seasons 1 to 8 end in March instead of May? and why did seasons 9-11 start too late? it seemed that instead of starting in September , season 9 started in the middle of November, 10
started at the end of October, and the same for the final season.
Why?

This is according to the episode guide at the following link:

http://www.cs.uu.nl/wais/html/na-dir/tv/mash/guide.html

As you can see, for seven of the first eight seasons the show actually ran first-run episodes into March. It's interesting that Season 4 ended in February. In those days the September through March season was pretty much the norm. Only seasons 9 and 10 ended later than March.

The airdates for 1980-1981 (Season 9) were delayed because of an actors' strike.
The airdates for 1981-1982 (Season 10) were delayed because of a writers' strike.

Season 11? Maybe all programming was still behind schedule because of the two previous delayed years??? Season 11 was also a bit shorter in number of episodes.



Season 1: 9/17/72 - 3/25/73
Season 2: 9/15/73 - 3/2/74
Season 3: 9/10/74 - 3/18/75
Season 4: 9/12/75 - 2/24/76
Season 5: 9/21/76 - 3/15/77
Season 6: 9/20/77 - 3/27/78
Season 7: 9/18/78 - 3/12/79
Season 8: 9/17/79 - 3/24/80
Season 9: 11/17/80 - 5/4/81
Season 10: 10/26/81 - 4/12/82
Season 11: 10/25/82 - 2/28/83


:D