September 2019 boasts the last Palindrome Week of the century

Tuesday marks the beginning of the final palindrome week of this century.

For 10 consecutive days, the date — written in the m-dd-yy format — will be the same forwards and backwards:

  • 9-10-19
  • 9-11-19
  • 9-12-19
  • 9-13-19
  • 9-14-19
  • 9-15-19
  • 9-16-19
  • 9-17-19
  • 9-18-19
  • 9-19-19

Palindromes are words, phrases or sequences that can be read the same forwards as backwards, and depending on which format one uses, palindromic dates can be rare.

In the mm-dd-yyyy format, for example, the first Palindrome Day in the current millennium (Jan. 1, 2001 to Dec. 31, 3000) was Oct. 2, 2001 (10-02-2001). The last Palindrome Day of the current millennium will be Sept. 22, 2290 (09-22-2290), according to Aziz S. Inan, an electrical engineering professor at the University of Portland.

Palindrome weeks — such as the one beginning Tuesday, Sept. 10, this year — are not so rare. Beginning in 2011, every year has had 10 consecutive Palindrome Days. In 2011, this occurred in January and has bumped one month later in each successive calendar year.

When writing the date in the m-dd-yy format, each century has nine years with 10 Palindrome Days in a row — the next time this will happen will be in the years 2111-2119.