As any Nintendo fan knows, March 31st 2021 is going to be an… interesting time for the Mario series. It’s the day when Super Mario 3D All-Stars is pulled from sale. It’s the day when Super Mario Maker on Wii U loses online support, with level uploads finally ceasing forever.

And it’s also the day when Super Mario Bros 35 will stop working altogether, relegating this interesting battle royale experience to the history books once and for all.

So many have been left wondering… why? Why is March 31st the shut down day for all these services and game sales? Why is Nintendo going with this date to close them down rather than a more obvious one, like December 31st or the game’s anniversary?

Is it because Nintendo wants to sacrifice Mario to save the word from COVID-19? Does Miyamoto plan to sell Mario’s soul to the devil, and March 31st is the one time the required incantations work as expected? Are astronomers predicting the end of the world on that date, due to a misreading of the Mayan Apocalypse prophecies!

Well maybe.

But more likely the answer is a lot more mundane. Basically, Japan’s fiscal year is not January 1st to December 31st, just like it isn’t in many countries.

Instead, it’s April 1st to March 31st. Hence for accounting and business purposes, companies generally want to make sure any major changes to their products and services happen by March 31st in a particular year, at least if they want to avoid extra complexities down the line.

So yeah. There’s no conspiracy here, nor is the March 31st date some random Nintendo choice made on a whim. It’s just the end of Nintendo’s fiscal year, and they want to tie up any loose ends before the new one begins shortly afterwards.

Hope that cleared everything up for you!