PORTLAND, Ore. (KOIN) — September 2019 will be a month full of “palindrome dates,” including Sunday, Sept 1.

A palindrome is a word or phrase that is spelled the same backward as it is frontwards, like race car. That same concept can apply to dates like 9/1/19 — aka 91/1/9.

The other 10 palindrome dates this month are between Sept. 10 and 19 — all 5-digit palindromes.

All the palindrome dates in September 2019. (Courtesy of Aziz Inan)

University of Portland professor Aziz Inan said September 10 is special because it’s what he calls a 7-digit palindrome date. It a palindrome when you include the whole year, 9/10/2019 or 9102/01/9!

September 2019 isn’t so special though, every year since 2011, one month has had 11 palindrome dates each year and they shift forward one month. Next year, instead of shifting to October, they’ll be in February.

In other countries, the palindrome dates are different because they write the date as 1 September 2019.

Inan said February 2, 2020, is special because it’s a palindrome any way you write it, like 11/11/1111 and eventually 12/12/2121.

There are 38 palindrome dates in the 21st century.