Yes, today is the Pythagorean theorem day. It is a day in which the sum of the squares of the first two digits (date and month) equals the square of the last two digits (of the year). Following this we have
16² + 12² = 20² (256+144=400).
The last Pythagorean Theorem Day was on 15 th August 2017 since
15² + 8² = 17² (225+64=289)
Pythagorean theorem days are of special interest because it doesn’t happen every year.
In fact, we can’t find any such day in the next 4 years! The upcoming day will be 24.07.2025.