A palindromic date is one whose digits read the same backwards once the slashes are dropped, so 22/02/2022 counts and 7/11/2026 does not. Read through each locale's default short date format in Unicode CLDR 48, the data most software formats dates from, the years 2000 to 2099 hold 322 palindromic dates for Singapore English and the same for Singapore Tamil. Singapore's Malay default gives 129. Its Chinese default gives 30. The long-form counts underneath are older than ours: Aziz Inan of the University of Portland published 38 month-first and 38 day-first dates, which our enumeration reproduces exactly, and the Farmers' Almanac page he co-wrote already covers year-first order and dates that work in every format. Across the twenty locale defaults we ran, the total goes from 9, for Hong Kong, to 322.
Defaults for Singapore's four official languages keep separate palindrome timetables
English and Tamil in Singapore both default to d/M/yy. Malay uses d/MM/yy and Chinese dd/MM/yy. In UTS #35, Part 4, d is the day without a leading zero and dd the day with one, M and MM do the same for the month, and yy is a two-digit year.
Each zero a pattern adds lengthens the digit string, and a longer string is harder to mirror. Padding the month takes Malay from 322 to 129. Chinese pads the day as well and lands at 30. Malaysia spreads wider: its Chinese default, y/M/d, gives 10 and its Tamil default 322, with English at 29.
These are software defaults, which operating systems and users override. CLDR records them as locale data rather than law.
US and ISO order call at identical dates once the zeros are written
When written with leading zeros, the month-first (MMDDYYYY) and year-first (YYYYMMDD) formats are palindromic for the exact same set of dates. A date works in both formats if the month and day (MMDD) are the reverse of the year's digits. For 2030 that is 0302, so 2 March 2030 works both ways, as 03022030 and 20300302. Over every day from 1000 to 9999 we found 331 in each order, and the two sets are identical.
From 2000 to 2099 each order has 12. Any year in that range, reversed, ends in 02, and in MMDD those digits are the day, so all 12 fall on the 2nd of a month. Day first with zeros (DDMMYYYY) reads the reversed year as DDMM instead, putting the 02 in the month slot: all 29 day-first dates fall in February, the last on the leap day of 2092.
Inan's month-first 38 is those 12 plus 26 written without zeros. Our two lists match the 38 that Live Science prints from his work, date for date.
Two-digit years turn Korea's default into a stopping service
CLDR gives no support for filing East Asia's year-first defaults together under ISO order. Mainland China and Taiwan both default to y/M/d, a four-digit year with no zeros on month or day, which gives 10 palindromic dates from 2000 to 2099, all between 2 October 2010 and 2 October 2019. Japan's y/MM/dd is the only one written with zeros, and it gives the padded 12.
Korea's yy. M. d. drops the century as well as the zeros, so 2 July 2027 becomes 27. 7. 2., digits 2772. A four-digit string only needs its outer and inner pairs to match, and Korea's default gives 322. Chinese national date standards are covered in our guide to the Chinese date standard that gets misquoted.
Every long-form order last shared a stop in February 2020
From 2000 to 2099, one date was a palindrome in all three eight-digit orders: 2 February 2020, which is 02022020 day first or month first and 20200202 year first. Inan and Melissa Mayntz call such dates "ubiquitous" palindromes, and their Farmers' Almanac piece already discusses them.
The day and month must be the same number, and the year those four digits reversed. We found 11 from 1000 to 9999. The next is 12 December 2121, then one per thousand years from 3 March 3030 to 9 September 9090. Dates before 1582 are proleptic, the Gregorian calendar run backwards.
The Hong Kong default runs no service again until 2101
Hong Kong's d/M/y, used by its Chinese and English locales, gives the fewest: 9 dates, all between 1 October 2011 and 9 October 2019. The next is 10 January 2101, 29,678 days after the last. The y/M/d default of China, Taiwan and Malaysia's Chinese locale has none left before 2100; its next is 2 January 2100, 29,312 days after 2 October 2019. Counted from 2001 to 2100 instead, that date lifts the China and Taiwan total to 11.
Inside 2000 to 2099 the padded orders' longest gaps tie. Day first, nine separate gaps last 2,903 days, one per decade, and 2026 sits inside one, from 22 February 2022 to 3 February 2030. Month first, three gaps share the longest, 3,684 days.
Measured from 7 November 2026, Singapore Malay last matched on 22 November 2022 and next matches on 13 November 2031, a gap of 3,278 days that ties with six others as the pattern's longest. Singapore Chinese next matches on 3 November 2030. Singapore English is 92 days away: 7/2/27, or 7 February 2027. Under the US default the same characters are next too, meaning 2 July 2027.
A grapheme-aware checker waves vowel signs and emoji through the barrier
Words are harder than dates, because what counts as one character depends on the script. Our palindrome checker composes text to Unicode's NFC form (UAX #15), then compares extended grapheme clusters, which UAX #29 uses to approximate user-perceived characters. Tamil காக is not a palindrome, because கா is one character and க another. Greek ΣΟΣ passes with case ignored, since final ς folds to σ. A skin-tone thumbs-up is two code points and one character, and 🇸🇬🇬🇸, Singapore's flag then the flag of South Georgia and the South Sandwich Islands, fails.
Until 7 November 2026 the checker compared code points after a punctuation filter that also deleted combining marks. With that filter on, as it was by default, Tamil காக, Hindi कीक and Thai ก่าก read as palindromes, ΣΟΣ failed, and a pair of emoji was deleted outright. With it off, the two flags passed.
Its Dates tab starts from today in Singapore. Set to 7 November 2026, it shows 07112026, 11072026 and 20261107, none a palindrome, and the nearest palindromic date either side under twelve written orders and the twenty locale defaults.
Buddhist-era years reroute the Thai d/M/yy line
The calendar is the other variable. CLDR's calendar preference data lists the Buddhist calendar first for Thailand, and a Buddhist-era year is the Gregorian year plus 543. Thailand's short pattern is d/M/yy, the same as Singapore English, but 7 November 2026 comes out as 7/11/69.
On our count that gives 321 for 2000 to 2099, one fewer than Singapore English, and moves the next one from 7 February 2027 to 17 January 2028, written 17/1/71. The same data lists the Republic of China calendar second for Taiwan and the Japanese calendar second for Japan, behind the Gregorian, so their default rows stand.
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