What if the Mexicans had it wrong and doomsday wasn't 12.21.12, but 12.21.21?

Maybe your right?  who knows I guess we have to wait and see what happens then:

There is no such thing but you can always pretend.

God in prayer what is this eclipse about December 4 2021 Acts 4:12 open my Bible the pharasisse and saddeucees ask Jesus Christ for a sign in the heavens

Mayans, not Mexicans, and why would their calendar change according to the numbers used in the calendar we use?

Why don't you go play these numbers in the enalot?

Are you talking about the Mayan calendar? It's a calendar. I have one in my kitchen. When it ends, the world doesn't end. I just get another calendar.

First, it was the Mayans. They all died out even before Cortez showed up, so long before what used to be the Mayan Empire became Mexico. Second, that's not possible because they didn't use base-10 numbers or start counting years from the birth of Christ, which makes what you're suggesting impossible as that Mayan year didn't end in 12 so couldn't be inverted into 21.

There've been countless predictions of the end of the world, or of some apocalyptic catastrophe that's going to wipe out humanity.

And the last time I checked, we're all still here :3 what makes you think this time will be any different?