Palindrome Date Calculator — Find Dates That Read the Same Backwards
A palindrome date is a date whose digits read identically forwards and backwards. Enter any four-digit year to check whether it contains a palindrome date in the US (MM/DD/YYYY), international (DD/MM/YYYY) or ISO (YYYY/MM/DD) format — and see the actual date if one exists.
How does this calculator work?
A palindrome date's 8-digit string (MMDDYYYY) reads the same forwards and backwards. For year Y₁Y₂Y₃Y₄, the candidate date is month Y₄Y₃ and day Y₂Y₁. If that forms a valid calendar date, the year has a palindrome. Year 2020 had 02/02/2020 — valid in all three major date formats.
Formula
How this is calculated
To test whether a year has a palindrome date in MMDDYYYY format, write the year as four digits Y₁Y₂Y₃Y₄ (thousands, hundreds, tens, ones). The 8-digit string MM DD YYYY is a palindrome when position 1 = position 8, 2 = 7, 3 = 6, 4 = 5 — which means Month = Y₄Y₃ and Day = Y₂Y₁. For example, year 2020: Month = 02, Day = 02 → 02/02/2020; the digit string "02022020" reversed is "02022020". If the resulting month and day form a valid calendar date, the palindrome exists.
For DD/MM/YYYY the same logic applies with day and month swapped: Day = Y₄Y₃, Month = Y₂Y₁. Interestingly, the YYYY/MM/DD format produces the same calendar date as MM/DD/YYYY (just formatted differently), because reversing YYYYMMDD gives DDMMYYYY and the mapping is symmetric.
Not every year has a palindrome date. Both the month and day derived by the reversal must fall within valid ranges (month 1–12, day 1–31) and form a real calendar date (e.g., February 30 is invalid). Years in the range 2000–2099 tend to be rich in palindromes because their digit structure often maps to small, valid month and day numbers.
Frequently asked questions
In MM/DD/YYYY format, 02/02/2020 was a globally celebrated palindrome — the same 8-digit string reads identically in MM/DD/YYYY, DD/MM/YYYY and YYYY/MM/DD, making it the first such date in over 900 years. The previous universal palindrome date was 11/11/1111.
In MM/DD/YYYY format, most years in the 21st century have exactly one palindrome date (or none). The 2000s were particularly rich — 01/02/2010, 11/02/2011, 02/02/2020, etc. DD/MM/YYYY format follows the same mathematics but recognises different dates as palindromes. Some years have palindromes in multiple formats simultaneously.
Because reversing an 8-digit string YYYYMMDD gives DDMMYYYY. The palindrome condition (string = its reverse) is symmetric: if MMDDYYYY is a palindrome, the corresponding YYYYMMDD string is also a palindrome by the same digit constraints. Both formats produce a palindrome on the same calendar date.
Also known as
TG we-Calculate Editorial Team. (2026). Palindrome Date Calculator — Find Dates That Read the Same Backwards [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/palindrome-date-calculator
TG we-Calculate Editorial Team. "Palindrome Date Calculator — Find Dates That Read the Same Backwards." TG we-Calculate. 2026. https://we-calculate.com/calculator/palindrome-date-calculator.
TG we-Calculate Editorial Team, "Palindrome Date Calculator — Find Dates That Read the Same Backwards," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/palindrome-date-calculator
@misc{wecalculate_palindrome_date_calculator, title = {Palindrome Date Calculator — Find Dates That Read the Same Backwards}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/palindrome-date-calculator}}, year = {2026}, note = {TG we-Calculate} }
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