No, you won't find it on your calendar. No, you won't get it as a paid holiday. No, it isn't widely recognized.
So just what is "Bad Saturday?"
"Bad Saturday" is what I call the day after Good Friday. Imagine you are, oh, the Apostle Peter. It's been a rough week. Your best friend ever rebuked you and called you "Satan". Then, if that isn't bad enough, the authorities pick up your friend. You try to defend, and even take off an ear, but it's no use. The guards haul off your Savior, beat Him miserably, then killed Him on a cross while the crowds jeered.
So there you are, and everything you've known and believed has just come to a crashing "thud." No more Jesus. No more walking on water. No more of His improbable sayings, no more miracle healings, all of it, gone. He's dead.
It's a bad Saturday.
Ah, but in a day, it's going to get better. Radically better. Miraculously better.
All that "three days" stuff Jesus kept talking about will finally make sense, perfect sense. The cloud which obscured His teachings will be swept away, the veil removed. Our Savior Jesus died, really died and rose from the grave! Oh He is so Lord!