A few times a year, we as sports fans are blessed with a day filled with sporting events. Recently, early May has been quite eventful, with baseball, the Kentucky Derby, Floyd Mayweather fights, NBA playoffs, NHL playoffs, and late-season premier league action (for those that observe). These are thrilling days, filled with the stress of just following it all (We can’t all afford to fly from the Derby to Vegas for the fight, you know). It’s an exciting day, but there’s always something missing….hmm….

There have only been twelve days, ever, where the MLB, NFL, NBA, and NHL have had games on the same day. Twelve! Ever! Jeb! Between the four leagues, there have been 387 seasons, and only twelve freaking times ever have the four overlapped. There have already been seventeen lunar eclipses since 2000, and everyone acts like they’ve seen a chupacabra shaking its hips with Elvis whenever one of those comes around.

This matters, because now that the Royals aren’t going to sweep the Mets, Sunday, November 1st, 2015, will be the thirteenth day, ever, where all four major North American sports leagues will have events on the same day. A Big Four Sports Day. Strangely enough, the last two Big Four Sports Day have also come on November 1sts, in 2009 and 2010. As if they weren’t rare enough already, there have only been three Big Four Sports Days since 1985.

In order for one of these days to occur, a lot has to go right. The World Series has to run into late October. The NBA has to start before November. The NHL has to not be locked out. And, on the rare instance that those three things have all happened, somewhere in the tiny window after basketball starts and before the World Series has ended, a Sunday has to come around. Yes, the NFL also has action on Mondays and Thursdays, but eleven of the twelve previous Big Four Sports Days have come on Sundays, with the one outlier being 2010, a Monday.

The first time all four leagues played on the same day was October 17th, 1971, which was the 25th season of the NBA. That means there were 25 eligible seasons before the first Big Four Sports Day occurred, but that’s only the second longest we’ve gone without a Big Four Sports Day. The gap between numbers 9 and 10 was over 26 years, between 10/27/85 and 11/4/01. Number 10 doesn’t even happen if not for the September 11th attacks that year, as its the latest a Big Four Sports Day has come in a year.

EDIT: Fixed some poor math pointed out to me by a commenter, gap between 9 and 10 was 26+ years, not “over 30 years” like I previously posted. Measure twice and use a calculator, or something like that.

EDIT 2: Wow, math is not good for me today. It’s 16 years. Meaning those 25 initial years ARE the longest.

The shortest gap between Big Four Sports Days? One week! Twice! In Back to back years! In both 1982 and 1983, the World Series played across two different Sundays where the NBA season had already commenced. That means that this insanely rare sporting alignment of stars, which has only happened 12 times and once went 5,852 days between occurrences, had FOUR occurrences over a span of 371 days. Those spoiled bastards probably got used to days like this.

So on Sunday, if you fancy yourself a true sports fan, it’s your duty to make sure you watch at least part of a game from each sport. You could go the extra mile too, and catch some Premier League or MLS Playoff action. After all, every year has at least a day or two where there aren’t any Big Four events at all, and who knows when the next Big Four Sports Day will come around. After all, if you aren’t overwhelmed by the amount of sports there are too watch, you’re doing it wrong.

Compiled list of all the results of Big Four Sports Days