Every Day Counts
Fermat Prime Days
Date of birth
Enter your date of birth. Find out when you will be celebrating!

Fermat Prime Days occur when your day age is a Fermat prime number.

Fermat primes are of the form 22n

As of 2011 these are the only known Fermat primes, and conjecturally the only Fermat primes.

We have yet to hear from someone who has held a Fermat Prime Day party.