The Calendar hole will go live in approximately 13 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 477th jacekwladzinski 657 95 10ms 7 Oct 2025 477th aalec 657 95 10ms 8 Nov 2025 483rd NickTheEASDude 🇺🇸 657 105 2ms 7 Oct 2025 484th msbranicky 656 136 3ms 1 Sep 2024 485th msbranicky 655 95 3,872ms 8 Jan 2025 486th Shanethegamer 🇺🇸 655 135 422ms 1 Sep 2024 487th albanian-laundromat 655 189 44ms 14 Sep 2025 488th lukechampine 655 200 255ms 7 Jun 2025 488th jerrandolph 655 200 264ms 21 Sep 2025 490th fgrosshans 🇫🇷 650 96 10ms 1 Sep 2024 490th mm1013g 650 96 11ms 2 Sep 2024 490th Mikey-Beep 🇬🇧 650 96 10ms 2 Sep 2024 490th JudeTyrrell 650 96 10ms 22 Sep 2024 494th TFeld00 🇩🇰 649 65 53ms 3 Sep 2024 495th ShiraJoseph 🇺🇸 649 109 9ms 22 Sep 2024 496th voytxt 🇨🇿 647 93 134ms 17 Apr 2025 497th msbranicky 646 203 257ms 1 Sep 2024 498th error256 645 106 13ms 18 Apr 2025 499th Waffle3z 645 107 2ms 2 Oct 2024 500th stefangimmillaro 643 71 819ms 3 Sep 2024 501st scpchicken 🇵🇼 643 97 248ms 8 Sep 2024 501st Carlettos1 643 97 12ms 14 Sep 2024 503rd mrxz 🇳🇱 643 110 9ms 22 Sep 2024 503rd weliveinhell 🇭🇹 643 110 9ms 28 Sep 2024 505th BlankSpruce 642 140 2ms 1 Sep 2024 506th stefangimmillaro 640 151 437ms 6 Oct 2025 507th emgordon154 639 113 112ms 14 days ago 508th aDwarfNamedUrist 638 138 119ms 4 Sep 2024 509th SirBogman 🇺🇸 637 73 308ms 23 Jul 2025 510th pickerj 637 98 11ms 13 Sep 2024 510th dtbao20 🇻🇳 637 98 16ms 30 Sep 2024 510th YAJUE114514 637 98 10ms 30 Jul 2025 513th stefangimmillaro 636 188 199ms 4 Jun 2025 514th emgordon154 635 40 3ms 20 Nov 2025 515th Shanethegamer 🇺🇸 634 72 861ms 1 Sep 2024 515th anter69 🇭🇺 634 72 858ms 25 Oct 2024 517th Ripick 633 127 392ms 6 Sep 2024 518th CaedenHarper 🇨🇦 632 112 10ms 22 Aug 2025 519th alexeldridge 630 99 10ms 14 Sep 2024 519th Just4FunCoder 630 99 10ms 14 Sep 2025 519th 0xjac 🇨🇭 630 99 10ms 24 days ago 522nd olleicua 🇺🇸 629 67 44ms 6 Sep 2024 523rd BalaM314 626 113 8ms 4 Feb 2025 524th Kacarott 🇦🇺 624 100 10ms 3 Sep 2024 525th cthierfelder 🇲🇨 624 193 77ms 5 Sep 2025 526th kmathis22 623 155 356ms 3 days ago 527th SirBogman 🇺🇸 622 59 158ms 23 Jul 2025 528th MeWhenI 🇻🇦 622 86 683ms 15 Sep 2025 529th DialFrost 🇸🇬 622 111 2ms 22 Nov 2024 530th KrausRaus 🇺🇸 621 114 11ms 1 Sep 2024 530th snoozingnewt 🇨🇦 621 114 9ms 12 Oct 2025 532nd Shanethegamer 🇺🇸 620 68 37ms 1 Sep 2024 532nd emgordon154 620 68 38ms 1 Sep 2024 532nd rvs314 620 68 40ms 24 Sep 2024 535th madex 🇩🇪 618 101 14ms 1 Sep 2024 535th RedzGoose 🇦🇺 618 101 10ms 15 Oct 2024 535th Flekay 🇩🇪 618 101 11ms 10 Jul 2025 538th lifthrasiir 🇰🇷 618 227 46ms 11 Dec 2024 539th Andrey-Plotnikov 615 115 9ms 30 Sep 2025 540th aliakseikalosha 614 144 373ms 5 Sep 2024 541st sciencejiho 612 102 10ms 13 Sep 2024 541st Papushkado 612 102 9ms 10 Nov 2025 541st JOrE20 🇺🇸 612 102 10ms 10 days ago 544th Natanaelel 🇸🇪 611 112 14ms 15 May 2025 545th Shanethegamer 🇺🇸 610 102 4,008ms 25 Oct 2024 545th dokutan 610 102 3,847ms 26 Oct 2024 547th BambooleanLogic 🇸🇪 610 116 9ms 19 Nov 2024 547th acollett89 610 116 9ms 4 Aug 2025 549th msbranicky 608 86 231ms 16 Sep 2024 550th julian-hoelz 606 103 10ms 16 Sep 2024 550th StefanHabel 🇨🇦 606 103 97ms 22 Mar 2025 552nd emgordon154 606 138 11ms 1 Jan 2025 553rd Arkadios200 602 132 96ms 11 Oct 2025 554th dokutan 601 76 815ms 3 Sep 2024 555th dokutan 601 147 399ms 3 Nov 2024 556th ComputerKWasTaken 🇺🇸 600 104 10ms 2 Sep 2024 556th elgan65536 600 104 9ms 23 Sep 2024 556th NickTheEASDude 🇺🇸 600 104 10ms 7 Oct 2025 559th Shanethegamer 🇺🇸 600 134 412ms 1 Sep 2024 560th inventshah 599 150 2ms 1 Sep 2024 First Prev 481–560 of 707 Next Last