It’s time to let the cat out of the bag. Although there are some fascinating idiom origins, one that people might also be curious about is, “for Pete’s sake!” And, for Pete’s sake, you should.

What does it mean to say “for Pete’s sake”?

The phrase essentially uses Pete a mild substitute for God or Christ in this expression of annoyance or frustration. It’s similar to the less-common, “for the love of Mike.” The switch to Pete makes the phrase more socially acceptable and less offensive. Replacing the words in this euphemism to make a saying more appropriate is also called a “minced oath.” If you want to avoid being rude, you’ll skip saying these words with offensive origins, too.

The origins of “for Pete’s sake”

People started saying “for Pete’s sake” instead as early as 1903, according to the Oxford English Dictionary citations. But there’s no confirmed reason why people use Pete instead of Tom, Jim, or any other name for that matter. One speculative theory in the Morris Dictionary is that someone replaced Jesus or God with another religious figure—St. Peter. That theory isn’t as out there as these everyday phrases with surprisingly dark origins.

Now that you know a bit more behind why people say, “for Pete’s sake,” you can celebrate For Pete’s Sake Day on February 26th. And don’t worry, this isn’t one of the words or phrases smart people never use.