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

A Zeisel Day occurs when your day age is a Zeisel number.

A Zeisel number, named after Helmut Zeisel, is a square-free integer k with at least three prime factors which fall into the pattern

px = apx - 1 + b

where a and b are some integer constants and x is the index number of each prime factor in the factorization, sorted from lowest to highest.

Who would not want to celebrate that?