The Calendar hole will go live in approximately 10 days. Why not try and solve it ahead of time?
PalindromemordnilaP in all languages in chars. Achievements Cheevos Holes Languages Medals Miscellaneous All Holes 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig 05AB1E ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig Experimental Language 05AB1E ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Hole All 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Experimental Hole Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Chars Time Submitted 641st snoozingnewt 🇨🇦 476 189 5ms 9 Oct 2025 642nd rucin93 🇵🇱 476 251 221ms 5 Sep 2024 643rd junkondo-jp 475 149 9ms 15 Dec 2024 644th KatieLG 🇬🇧 475 292 7ms 1 Sep 2024 645th rboath 470 159 109ms 18 Dec 2024 646th janAkali 🇷🇺 470 171 385ms 17 May 2025 647th DialFrost 🇸🇬 467 207 461ms 24 Sep 2025 648th R4z0rX 466 152 9ms 1 Sep 2024 649th iczelia 🇩🇪 463 194 2ms 11 Oct 2025 650th Stockoh 🇫🇷 456 137 11ms 17 Oct 2024 651st two-bad 🇬🇧 454 156 9ms 4 Oct 2024 651st JOrE20 🇺🇸 454 156 9ms 19 days ago 653rd brimstonetrader 452 138 10ms 17 Oct 2024 654th snoozingnewt 🇨🇦 449 186 8ms 1 Sep 2024 655th msbranicky 445 269 217ms 1 Sep 2024 656th Shanethegamer 🇺🇸 438 115 2ms 1 Sep 2024 657th ehulinsky 🇺🇸 432 122 3ms 3 Apr 2025 658th Yax42 🇫🇷 431 224 452ms 5 Oct 2025 659th aksyristos 418 101 41ms 17 Nov 2024 660th MeWhenI 🇻🇦 411 260 94ms 13 Jun 2025 661st HunterC14 403 155 10ms 21 Oct 2024 662nd Jacob385 402 240 398ms 4 Sep 2024 663rd bac0id 402 266 2,912ms 10 Jan 2025 664th zakariamouhid 398 178 10ms 14 Sep 2024 665th galloj 🇨🇿 396 101 10ms 4 Sep 2024 666th Naitzirch 🇳🇱 395 158 11ms 3 Jul 2025 667th varhammer 🇷🇺 389 235 8ms 20 Oct 2025 668th Apzyte-Gamer 378 165 10ms 28 Oct 2024 669th CyberTapir 369 169 10ms 1 Sep 2024 670th IISResetMe 366 127 359ms 17 Nov 2024 671st Giantnoodlemonster 365 246 2ms 27 Sep 2024 672nd MeWhenI 🇻🇦 363 135 7ms 26 Sep 2024 673rd rollershutter 355 176 10ms 18 Nov 2024 674th Mikey-Beep 🇬🇧 354 193 14ms 13 Aug 2025 675th nephila-nacrea 🇬🇧 283 132 3ms 4 Sep 2024 676th AidanWalter 282 221 11ms 3 Jan 2025 677th bidger 262 369 411ms 20 Sep 2024 678th KatieLG 🇬🇧 262 459 1,375ms 15 Sep 2024 679th timhaj 🇸🇮 261 239 10ms 19 Sep 2024 680th KatieLG 🇬🇧 260 460 191ms 15 Sep 2024 681st snoozingnewt 🇨🇦 241 444 1,202ms 6 Oct 2025 682nd KatieLG 🇬🇧 200 401 125ms 15 Sep 2024 683rd KatieLG 🇬🇧 176 398 7ms 15 Sep 2024 684th KatieLG 🇬🇧 171 768 259ms 15 Sep 2024 685th KatieLG 🇬🇧 113 466 3ms 15 Sep 2024 686th Msleizak 🇫🇷 110 424 283ms 7 Feb 2025 687th KatieLG 🇬🇧 103 937 406ms 15 Sep 2024 688th KatieLG 🇬🇧 86 1,032 399ms 15 Sep 2024 689th dokutan 64 1,663 92ms 23 Apr 2025 690th dokutan 54 1,663 2ms 23 Apr 2025 691st darrenks 0 10 101ms 19 Apr 2025 691st lyphyser 0 10 92ms 25 May 2025 693rd 2bular 0 11 88ms 23 Mar 2025 693rd Natanaelel 🇸🇪 0 11 86ms 25 Mar 2025 693rd plcc0 0 11 106ms 5 May 2025 696th kg583 🇺🇸 0 12 215ms 14 May 2025 697th lyxal 🇦🇺 0 14 673ms 17 May 2025 698th namelessiw 0 16 145ms 5 Nov 2025 699th plcc0 0 17 677ms 20 Mar 2025 700th GolfingSuccess 🇬🇷 0 28 130ms 13 Aug 2025 700th Nxllpointer 0 28 3ms 10 Nov 2025 702nd KatieLG 🇬🇧 0 29 4ms 9 Feb 2025 702nd Shanethegamer 🇺🇸 0 29 3ms 29 May 2025 704th AlephSquirrel 0 30 4ms 1 Jul 2025 705th ovs-code 🇩🇪 0 39 14ms 8 Jun 2025 706th GolfingSuccess 🇬🇷 0 75 2ms 5 Aug 2025 707th dokutan 0 86 68ms 28 Jun 2025 708th sean-niemann 🇺🇸 0 90 91ms 27 Apr 2025 709th HumanoidCPU 0 111 84ms 22 Nov 2025 710th edsrzf 🇳🇿 0 135 184ms 26 Jun 2025 First Prev 641–710 of 710
