4.1: Welcome to Korea + 4.2: Change of Command (1 week, 6 days)
Note: I've combined the day count for the first two episodes of the fourth season because they essentially occupy the same space of time. Allow me to explain.
The season opener, Welcome to Korea, see's Hawkeye come back from leave only to find out Trapper has just left. Apparently he got orders to go home 3 days before Hawkeye returned. This means that the start of this episode represents the fourth day of a series of events, 3 days of which took place off camera before the episode even started.
Hawkeye's travel to try and say goodbye to Trapper before he leaves, and his return to the 4077 with B.J all take place on the one day (Day 4). The final scene, where Potter arrives to take command (on 19 September 1952, for those who are interested) represents practically the end of a two week period.
How did I come to this conclusion, you might well ask?
Good question. Bear with me here, because this is where it gets a little complicated. But it's made easier if we do this in dot point form.
- Days 1 to 3: Happens off-camera before the episode begins. Trapper gets his orders to go home. He waits as long as he can for Hawkeye to return from Tokyo.
- Day 4: Trapper leaves for the airport. Later, Hawkeye returns from Tokyo and learns Trapper went home. He accompanies Radar to the airport to say goodbye to Trapper but misses him by 15 minutes. Hawkeye and Radar pick up B.J and bring him back to the 4077 by the late afternoon.
- Days 5 through 11: Happens off camera. Hawkeye and B.J, according to a line of dialouge by Potter in 4.2, set fire to the latrines at some point during this time, causing Frank to put them on report. We also know that a week passes due to a comment by B.J in episode 4.6 (The Bus) that he spent "a week with Frank in command."
- Day 12: Potter arrives to take command in a scene that initially takes place in 4.1 but is repeated in 4.2. Later in the day, casualties arrive and he and the other doctors all go into surgery.
- Day 13: The final scene of 4.2 takes place in the Swamp at 3am, after surgery. Hence, 1 week and 6 days worth of time have now passed since the beginning of episode 4.1.
4.3: It Happened One Night (1 day)
4.4: The Late Captain Pierce (1 day)
4.5: Hey Doc (1 day)
4.6: The Bus (2 days)
4.7: Dear Mildred (1 day)
4.8: The Kids (2 days)
MORE TO COME...