M*A*S*H Timeline

With contributions from Kara and Big Daddy O’Reilly.


It’s hard to believe that eleven years worth of stories were supposed to have taken place in the three years of the Korean War. To get around this time problem, the writers of M*A*S*H decided not to worry about it and concentrate instead on telling quality stories. Still, it is interesting to try to piece together a timeline for the series using dates mentioned in a variety of episodes.

When Do Colonel Potter and B.J. Arrive?

Perhaps the most confusing timeline issue when Colonel Potter and B.J. arrived at the 4077th. During the teaser at the end of “Welcome To Korea” (Season Four), Colonel Potter’s arrival is said to take place on September 19th, 1952. However, in the episode “A War For All Seasons” (Season Nine), we see Colonel Potter and B.J. at the camp on New Years’ Eve 1951, and in “Death Takes A Holiday” (Season Nine) Potter and B.J. are there for Christmas 1951. April Fools’ Day 1951 finds Colonel Potter and B.J. there as well, seen in “April Fools” (Season Eight).

Also, the episode “‘Twas the Day After Christmas” (Season Ten), should be set the day after Christmas 1952, seeing as Christmas 1951 was “Death Takes A Holiday.” Christmas 1952 would be the last Christmas of the war, since it ended in September 1953. However, in “Trick or Treatment,” which takes place after “Death Takes A Holiday,” we see a Halloween party, meaning it is October 31st, and apparently 1953.

How is all this possible? The most likely solution is that the writers realized after “Welcome To Korea” that they had made Colonel Potter and B.J. arrive too late in the war, that Trapper and Blake shouldn’t have been there for a year. That explains how Potter arrives in 1952 but is shown in 1951. It doesn’t explain Halloween of 1953, which can’t be explained as anything more than a simple mistake.

Kara contributed the following:

“And also in the episode “Dear Sis” I believe that is another Christmas episode which can’t really be explained either. unless we assume Trapper and Henry were only there for a couple months. I agree with you. The writers must have gone back and repeated time over again because the series continued for so many years. They needed more time so they went back and rewrote some in.”

The following timeline is simply an attempt to chart some of the dates given in episodes of M*A*S*H. We all know there is no way to cram eleven years worth of episodes into three years of war. So keep that in mind. Dates in italics took place in reality.


June 25th, 1950
The North Koreans cross the 38th Parallel and start the Korean Conflict.

Presumably at least the first season of M*A*S*H is supposed to take place during 1950; at the very start of “M*A*S*H – The Pilot” the subtitle “Korea 1950” is shown on the screen. However, in “Requiem For A Lightweight,” the third episode of the first season, Henry states that he can’t use the same fighter in a boxing tournament that he used “last year.”

The entirety of Season One took place during less than nine months, because Henry’s wife gave birth stateside in “Showtime” and as Radar noted, Henry must have been present for “the important part” of making a baby.

September 10th, 1950
Margaret tells Klinger it is Independence day and he replies that it is September 10th (“Lil“). This can’t be explained unless we assume it is September 10th, 1950 since it takes place before the April Fools Day episode 1951.

September 19th, 1950
Colonel Potter’s last stint in surgery before coming to the 4077th (in “Welcome To Korea” it is stated twice that Colonel Potter hadn’t been in surgery in two years, this could be a rough estimate).


April 1st, 1951
Colonel Potter tries to keep the camp from playing any practical jokes during April Fools’ Day, as a stiff-nosed Colonel is coming for a visit (“April Fools“).

June 1951?
The Interview” is said to take place during “the second year of the war,” which could mean it occurs anytime between June 1951 and June 1952.

August 9th, 1951
Hawkeye is fed up with army life, and the 4077th, and hides out in Rosie’s Bar, as eventually the rest of the camp does too; all the while, Margaret encounters Jack Scully for the first time, Klinger plays Craps with some Korean locals, and Radar discovers a passed out major with no records on him (“A Night a Rosie’s“).

August 10th, 1951
Hawkeye and B.J. wake up in the now trashed out Rosie’s Bar, where the major whom was found passed out finally awakens, last remembering he was in Hawaii… on the night of July 4 (“A Night a Rosie’s“).

September 11th, 1951
Private Rich is wounded while in combat, sustaining a throat injury, and is air lifted to the 4077th, where he undergoes surgery, and awakens in Post-Op, next to an obnoxious patient, who tries to act like he’s in more pain than he really is in order to get better care, and lengthen his stay (“Point of View“).

September 12th, 1951
Rich wakes up the next morning, and sees what an average day is like at the 4077th, including Margaret giving him a sponge bath, Klinger giving him a tour of the camp via wheelchair, communicating with Colonel Potter and Hawkeye through a note pad which he is using to write to his parents (which is date 9-12-1951). Rich later suddenly has trouble breathing, and needs to be rushed back into O.R. (“Point of View“).

September 12th, 1951
The 4077th sets up near the front (in “Welcome To Korea,” Hawkeye states that he had lived with Trapper for over a year and Trapper left somewhere around September 12th, 1952).

September 13th, 1951
Rich awakens and learns that his fracture larynx was the cause of his sudden breathing problem, but he is now able to speak more coherently when his breathing tube is squeezed (“Point of View“).

September 19th, 1951
Hawkeye stole a steam shovel from the Tokyo Provost Martial (according to his record in “Change of Command“, Colonel Potter said that “a year ago…” which could be a rough estimate).

October 17th – 22nd, 1951
Radar records the weekly report of the 4077th’s antics, including Sidney Freedman’s first observation of Klinger, and Trapper’s patient dying from contaminated blood after the I.V. is smashed by a berserk Chinese P.O.W. in O.R. (“Radar’s Report“).

December 25th, 1951
B.J. works to keep a dying man alive until December 26th so that his children don’t have to remember Christmas as the day their daddy died (“Death Takes A Holiday“).

December 31st, 1951
On New Year’s Eve, the 4077th looks back on 1951 (“A War For All Seasons“).


June 13th, 1952
Radar receives his study guide for a correspondence course in enrolled in for the Las Vegas Writing School in (as stated in “The Most Unforgettable Characters“; this episode also features Hawkeye and B.J. staging a fight for Frank’s birthday the same day, which conflicts with Frank’s birthday in “For Want Of A Boot,” which takes place during the middle of winter… unless that was his half birthday).

September 9th, 1952
Trapper receives his orders to be shipped stateside (this occurred 3 days before he left, as stated in “Welcome To Korea“).

September 9th – 10th, 1952
Trapper got drunk (stated in “Welcome To Korea” that he was drunk for two days before ).

September 12th, 1952
Trapper John leaves the 4077th, B.J. Hunnicut arrives at the 4077th (if the next episode took place a week from this one).

September 19th, 1952
Colonel Potter arrives at the 4077th to take command from Frank Burns, replacing the late Henry Blake as commanding officer (“Welcome To Korea“).

October 5th, 1952
Colonel Potter starts 6 days of R&R, leaving Frank in charge (“The Novocaine Mutiny“).

October 9th, 1952
Clete Roberts returns to interview the staff of the 4077th a second time (“Our Finest Hour“).

October 11th, 1952
Hawkeye assumes command after being in charge goes to Frank’s head. He is later brought up on charges (“The Novocaine Mutiny“).

December 26th, 1952
Colonel Potter has the enlisted men and the officers switch places for a day (“‘Twas the Day After Christmas“).


April 22nd, 1953
Klinger tells “Captain” Schaffer that by April 22, he will have been wearing ladies’ dresses to buck for a Section-8 for exactly two years (as stated in “Fade Out, Fade In“), which suggests he would have been drafted, and shipped out just before April 22 of 1951.

July 4th, 1953
Members of the camp hold a party on a beach in Inchon, on the way back they are almost spotted by North Koreans, in order to keep from being heard a Korean mother smothers her baby, which causes Hawkeye to become mentally unstable (“Goodbye, Farewell, and Amen“).

July 11th, 1953
Hawkeye returns to the 4077th after being treated by Sidney (if he was gone for a week after July 4th).

July 27th, 1953
The Korean War ends when the cease-fire goes into effect 12 hours after the armistice was signed.

September 26th, 1953
In the first episode of AfterMASH, Sherman Potter writes a letter to Klinger informing him of his reconciliation with his wife after returning from Korea.

October 31st, 1953
The 4077th has a Halloween party, and Father Mulcahy performs a “miracle” (“Trick or Treatment“).

Last Updated October 19th, 2013

29 Replies to “M*A*S*H Timeline”

  1. I like how you have all the dates listed. I made a M*A*S*H chronology for my website and the dates just don’t line up. They’re like the stardates in Star Trek, they go backward and forward except the camp isn’t traveling at warp speed. The sad fact is that television writers pay far less attention to continuity than fans do. I look at it this way: In the novel MASH, Hawkeye arrives in November of ’51. They raise money for Ho-Jon in June of ’52 (Pilot Episode) and Ho-Jon leaves in August (end of season 1). In season 10, instead of dates, there are mentions of Eisenhower running for president (Nov ’52) and taking office (Jan. ’53) and the war ends in July. As I say on my site, this order sort of makes sense if you ignore most of the dates given in the TV series. I say “sort of” because of course the book and the show don’t M*E*S*H together well, because Hawkeye is actually Trapper and goes home in Feb. ’53, Major Burns is two different people who go home in ’51 and ’52, Henry doesn’t go home (or die) and there’s no Col. Potter.

    1. I remember while the show was in its original run, the timeline was discussed often. When the show first aired, no one ever considered the possibility of an 11 year run for a TV series set in a 3 year war. Timeline conflicts were inevitable. Taking the only logical approach, the writers and producers, simply ignored the timeline problem and used dates without regard to timeline continuity.

      1. Yeah – keep in mind that back in those days TV shows generally made no attempt at producing a coherent timeline. Generally speaking, it was like all of the episodes occurred at the same time – anything that would produce “long term character growth” was avoided so that the “starting situation” for all episodes are the same. Of course when casting changes that’s hard to do perfectly.

        I remember Babylon 5 as the first show I watched that told a “master story” and thus had a required order for all of its episodes. And since then of course this has become commonplace – modern viewers are more sophisticated and demanding.

  2. I’ve got a new one for you RJ:

    In “Hot Lips in Back in Town,” there’s a small calendar in the Nurses’ Tent that reads December… the year is a little hard to make out, but it looks like it might be 1952… I wouldn’t swear to it though (especially considering it seems like most of Season Seven took place in 1951).

    It’s also strange that the calendar would say December, because its clearly not a winter episode: no one is wearing coats and parkas, and no one’s complaining about the frigid cold.

  3. In 9-14 (#212) – Oh, How We Danced: Hawkeye says to Winchester, “Charles, it’s only a routine inspection tour. Pork Chop Hill’s already been taken!”

    Pork Chop Hill has been taken on April 18, 1953, its defenses were rebuilt during May and June 1953. On the night of July 6, Chinese offensive started, and on July 11, Pork Chop Hill was lost. This puts the episode somewhere between the end of April and the beginning of July.

  4. I think that no one had any idea how long the show would last. The creators probably figured the show might last for 2 or 3 seasons, so there was no concern at first about using up Christmas episodes, etc.

  5. Note-the last factually correct mash episode was “the late captain pierce”. Which takes place in December 1952. (President elect Eisenhower trip to Korea after being elected president)
    After that the writers turned the timeline back to 1950-in a real timeline Winchester wouldn’t have arrived until about April-may of 1953
    By the way mash won’t on for far too long-the late captain pierce should have been Hawkeyes swain song exit from the show…too bad that their couldn’t have been a aftermath where Hawkeyes has to go to prison for the 7 months of the war he deserted from-or make it up by being head of a Indiana veterans hospital along with the rescued Henry Blake-who also have to work off his missing years-all the while Hawkeyes has to feud with the hospital administer-general frank burns!,

  6. Cannot understand how a show with so many dramatic errors could ever be considered for awards for writing.

    Hawk-eye has a sister and his mom was alive in the first years. The later he is a single child and mom died when he was a kid.

    Margaret’s dad comes back from the dead.

    Henry’s wife’s name changes. He has only 2 daughters and a new born son in season 1. But in season 3 his son is much older.

    The 4077th got movies before they were even filed. They got to see the Blob which did not come out till 1958.

    Radar does imitation of John Wayne from McLintock which did not come out till 1963.

    Constant mention of Godzilla which did not come out till 1954 in Japan and did not come to US till 1956.

    Potters child changes from a son to a daughter. and Grand child from a grand daughter to grand son.

    Margaret and Hawkeye demonstrated a procedure using a clamp which was not created till later on in the season.

    In one of the dear dad episode he mentions an argument between Margaret and Frank which did not happen till the next season

    1. Not to mention when I Corp sent the psychiatrist to check out the staff to see if they should be disbanded. The officer that sent him mention they company clerks name was Radar O’reilly. A nickname is never on a 401 file.

  7. I just ignore the years on the show that are mentioned. Episode 1 takes place just after the Korean War breaks out, the last show is when it ends, and all the stuff takes place in between in order with each one beginning the day after the previous episode.

  8. I am a big fan of MASH, but I never thought much of the timeline. Now you have me thinking, I don’t know the episode but the storyline was about the 1951 Dodgers/Giants pennant race. Potter didn’t arive till 1952. Still love the show!

  9. My theory is it took place in some alternate reality where there is a weird time loop where even their realities kept changing. There’s the explanation.

  10. The pilot episode, states it is 1950. Ignore the pilot episode, it doesn’t exist in the timeline.

    In the Season 8 episode, Heal Thy Self, a replacement surgeon, mentions practicing medicine, during a battle in the
    Pusan Perimeter, which occurred in the very early days of the war. Hawkeye just read about it, so he wasn’t even drafted yet when that occured. Winchester is there, so that episode must have occured in 1953, just weeks before Hawkeye’s own breakdown, as it is hinted at during the coda.

  11. It would have been a MASH ending in Margarets wedding…if at the end it was Houlihan…who finaly found love…only to be In the transport plane that was shot sown instead of that drunk slob Henry Blake…why was she keep on and Blake killed off? I guess her character was more popular than he was….incidently in real life..MASH 4077 97% recovery rate of the wounded would actually have ben – 10…because Blake, potter, hawkeye, Trapper John, BJ, Winchester, Houlihan….were all chronic alcoholics to drunk to operate …and Burns was so incompent…any patient of his would have been doomed…

    1. The actor who played Henry Blake, like other actors in the 70s, was convinced he was the star of the show. He decided to leave the show on his own and do s separate sitcom unrelated to M*A*s*H. That is why the writers killed him off when he left. They were pissed st him. No one in the cast knew about the ending, which is why they were all actually shocked when Radar made the announcement about the plane crash.

  12. You have to remember the show was on on for 11 seasons so there bound to be goofs. Also we as audience were looking at week after week Where I take the show as segments and they just pick random events. It was and still is good show . I watch because it makes me laugh.

  13. In season 6 Episode 22: Potter’s Retirement

    At one point Charles tells Colonel Potter, “The first open-heart surgery in medical history has just been done successfully.” This operation took place on May 6, 1953. However, the episode takes place on the day of the Kentucky Derby, which in 1953 was run on May 2.

    Also Charles complains that he has been at the 4077th for 6 months. Putting his arrival in December 1952

  14. A few years ago, I attempted to tell my kids stories about things I did when I was a teenager was often fouled up by dates and what happened first and with whom. Given that Hawkeye is the one constant in the show, perhaps considering it to be him telling stories to his family, some forty or fifty years later, would help the inconsistencies. Sort of like How I Met Your Mother.

  15. When McLean Stevenson and Wayne Rogers left, the producers probably assumed that the show would only go on for another season or two tops. Hence the late timeline. It was rare for a TV show back then to survive major cast changes and I’m surprised CBS renewed it for Season 5 after the Season 4 dip. But luckily the network gave the audience more time to adjust to the new dynamic of the show.

  16. This was a fun read. The timeline wasn’t anything I ever really thought about. You can add the 1952 Helsinki Olympics to your timeline. Thanks for posting.

  17. I have a few additions to the timeline. The stateside gathering in “The Party” likely takes place March 28th, 1953. And I’m guessing Father Mulcahy’s letter to his sister was written December 16th, 1951 meaning she received the letter on Ash Wednesday which was February 27, 1952.

  18. I actually find the anachronisms and timeline inconsistencies in M*A*S*H to be quite amusing. My favorite M*A*S*H anachronism: Radar’s comic book collection. I know he had a knack for “acquiring” things, but how does someone living in early 1950’s get comic books featuring characters (like the Avengers and Spider-Man) that created in the 1960’s?

  19. Another problem with the “M*A*S*H” timeline: when Hawkeye uses open-heart massage on a patient, and (temporarily) saves his life, we are told in a PA announcement at the conclusion that General Mark Clark has just succeeded General Ridgeway (who succeeded General MacArthur) as commander of the U.N. forces in Korea. Clark succeeded Ridgeway in May 1952, only 14 months before the war ended. But Frank and Henry are still at the unit, and Margaret still hasn’t met Donald Penobscot. (That leaves an awful lot of the series to go). Also, we are told during the episode that the night’s movie is “Godzilla and the Bobbysoxer”. Leaving aside the fact that there is no such movie (obviously), the entire “Godzilla” franchise didn’t even begin until 1954, the year after the war ended.

  20. The timeline is all bonkers, and you shouldn’t really try to make sense of it all cause there is none. The writers and producers back when the show first started had no idea how long the show would be on the air obviously, since shows get cancelled all the time. No one knew the show would last for 11 seasons/years. I love this show regardless though. It’s now February of 2020 and the show still makes me laugh no matter how many times I watch it.
    I just noticed though in the episode 6 of season 9, “A War For All Seasons,” the gang at the 4077th are celebrating New Years Eve 1950 at the beginning of the episode. You see Colonel Potter with a sash around him that reads “1950” and on the wall in the background it says “Happy 1951” and throughout the rest of the episode they reminisce about the events during 1951, including the Giants winning the pennant. But then at the end of the episode you see Colonel Potter with a different sash around him that says “1951”, and the signs on the wall now read “Happy 1952.” Yet Colonel Potter didn’t join the 4077th till 1952 as it was stated the beginning of season 4. So how was he there for New Years Eve 1950 and 1951???? As I said BONKERS!

  21. In the final episode, Margaret writes in the telegram to her uncle recommending Winchester for the job that she knew him for two years. Since the final episode took place June-July 1953, it means that Winchester arrived at the 4077th in spring 1951

  22. Each of the “replacements” were on the series longer than the “originals” (Potter and BJ for 8 seasons vs Henry and Trapper for 3 seasons and Winchester’s 6 seasons vs. Frank’s 5 seasons). Somewhat illogical to think the originals were there longer than their replacements in terms of the war. TV writers frequently have to recon storylines etc. The writers must have realized late in the series that their earlier references to specific dates (eg Potter arriving in September 1952) had to be corrected. So, in the end, Henry and Trapper were only there for a few months , Potter and BJ arrived at least in 1951 if not late 1950.

  23. wasn’t there a repeat plot when Hawkeye, trapper and frank do an exchange of wounded with the chinese, then Hawkeye, BJ and frank do the same exchange in another episode??

  24. We can assume that Henry and Trapper were there for a year, based on Hawkeye’s line in the first episode of the 4th season, “Welcome To Korea”, when Hawkeye tells Frank “For the last year, [Trapper] kept me from killing you.”. Sorry if this was previously mentioned. i haven’t had time to read the whole page yet.

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