Finding the date of Adventure Time’s Great Mushroom War (again)
So a while ago I made a post where I tried to narrow down the date of the Great Mushroom War. My conclusion was that it occurred sometime between the years 2000 and 2008. However, I have since realised that we can do even better.
During the episode Ketchup, BMO tells the story of the “Moon Lady”, who can only come out during lunar eclipses. But I only recently noticed that this detail was not made up by BMO: in the background of the pictures of Marceline and her mother, an actual eclipse is taking place.
Eclipses are rare events which happen on specific dates, and we can use other details in the episode to narrow down the specific eclipse that this might be.
- Even though BMO talks about a lunar eclipse, the photograph actually looks more like a solar eclipse. In the interest of completion I will consider both kinds of eclipses.
- The eclipse is total.
- Given Marceline and her mother are wearing beachwear, it is safe to assume that it is summer.
- Given that Marceline and her mother live in a van and probably can’t afford to go on holidays to the other side of the world, the photograph was probably taken in the United States.
- In the same episode, the photographs are kept on a USB drive. These weren’t invented until the year 2000, as I mentioned in my previous post on this topic.
So we’re looking for a total eclipse that occurred during summer after the year 2000 and was visible from the United States. There are in fact only four eclipses before the year 2040 that meet these criteria.
- Lunar eclipse of August 2007
- Solar eclipse of August 2017
- Lunar eclipse of June 2029
- Lunar eclipse of August 2036
Now, it’s fairly well established that the Great Mushroom War doesn’t take place in the future, or even the present. The businessmen and Patience St Pim both have keypad mobile phones when they are thawed from the ice in their debut episodes, suggesting that the Great Mushroom War occurred before smartphones became abdundant. This would indicate that the lunar eclipse of August 2007 is the most likely candidate for the eclipse we see in the photographs during Ketchup.
So we have refined our lower limit, from 2000 all the way up to 2007. In my previous post I made the case that the Mushroom War couldn’t have started after 2008, because the United States used F-117 bombers as seen in Bonnibel Bubblegum, and those were taken out of service in that year. However there are problems with that assumption. Those planes are sitting in hangers somewhere to this day, and it’s conceivable that the US could bring them back into service in the event of a total war. Additionally, the divergent timeline of Adventure Time might mean they were never removed from service in the first place. So let’s use something else to find our upper limit.
We know that Marceline was seven years old during the flashback in the episode Simon & Marcy, because Simon says so. We also know that the episode’s prologue and epilogue take place exactly 996 years later. Finn is 14 years old at this point. Later, during the arrival of the Purple Catalyst Comet, Finn is 16; a two year difference. Why is this relevant? Well, we know that the catalyst comets hit once exactly every thousand years. Additionally, it is usually assumed that the war-time comet coincided pretty closely with the end of the war, due to hints like the comet seen in Finn the Human, and Simon’s diary from Friends Forever. So let’s trace this all back.
The Mushroom War occurs. A thousand years later, The Comet takes place. Two years before that, the prologue/epilogue of Simon & Marcy takes place. And 996 years before that, the flashback takes place. From this we can conclude that the flashback in Simon & Marcy took place two years after the Great Mushroom War, and therefore Marceline was five years old when the world ended.
In the photographs from Ketchup, Marceline is two at the very youngest given she’s running about. So the Mushroom War must have occurred within two or three years of those photographs being taken.
That gives us a final date range of summer 2007 to early 2010. And do you know what else happened in early 2010? The premier of Adventure Time. A neat coincidence.
So that’s my new headcanon. The photos in Ketchup were taken in August 2007, and the Great Mushroom War ended at the same time Adventure Time premiered in real life, in April 2010. Thank you for coming to my TED talk.
As usual, none of this was intended by the show’s writers (unless they are a lot more committed to historical accuracy than I give them credit for) and shouldn’t be taken seriously.
[slow clap]
Jagm with the numbers!
Obsessed with this take. 🖤








