Today is not April Fool’s Day. I can prove this in several ways:
Proof #1: Was yesterday April Fools’ Day? No. Was the day before yesterday April Fools’ Day? No. Hence, by induction, we may conclude that today is not April Fools’ Day.
Proof #2: April Fools’ Day only happens once a year. So, the probability that today is April Fools’ day is 1/365. That’s almost 0.
Proof #3: If today were April Fools’ day, there would be unanimous consensus about the fact, but there isn’t, because I disagree.