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 160th Natanaelel 🇸🇪 865 35 32ms 1 Sep 2024 160th 4hg 🇺🇸 865 35 33ms 5 Sep 2024 163rd error256 865 93 532ms 24 Jul 2025 164th error256 864 72 3,794ms 24 Oct 2024 165th voytxt 🇨🇿 863 82 9ms 1 Sep 2024 165th dmrichwa 🇺🇸 863 82 9ms 2 Sep 2024 167th JayXon 🇺🇸 862 53 840ms 2 Sep 2024 167th pardouin 🇫🇷 862 53 878ms 4 Sep 2025 169th error256 862 112 453ms 24 Sep 2025 169th sean-niemann 🇺🇸 862 112 490ms 24 Sep 2025 169th MeWhenI 🇻🇦 862 112 453ms 7 Nov 2025 172nd GrayJoKing 🇦🇺 861 57 6ms 20 Mar 2025 173rd kumavale 860 139 223ms 28 Oct 2025 174th edsrzf 🇳🇿 859 84 100ms 19 days ago 175th MeWhenI 🇻🇦 858 59 21ms 13 Jun 2025 176th duckyluuk 🇳🇱 857 49 5ms 24 days ago 177th ovs-code 🇩🇪 857 61 313ms 1 Sep 2024 178th JayXon 🇺🇸 856 94 530ms 23 Jul 2025 179th DialFrost 🇸🇬 856 103 172ms 21 Nov 2024 180th KasperKivimaeki 🇫🇮 856 105 2ms 17 Aug 2025 181st MeWhenI 🇻🇦 854 57 8ms 1 Sep 2024 182nd JayXon 🇺🇸 854 94 103ms 10 Sep 2024 183rd edsrzf 🇳🇿 854 107 6ms 19 Oct 2025 184th tayloia 🇬🇧 853 83 9ms 1 Sep 2024 184th Lv0Sys 🇵🇱 853 83 10ms 10 days ago 186th DialFrost 🇸🇬 852 61 729ms 31 Aug 2025 187th JayXon 🇺🇸 851 87 2ms 20 Sep 2024 188th snoozingnewt 🇨🇦 850 88 122ms 22 Nov 2025 189th JayXon 🇺🇸 849 105 3ms 17 Nov 2025 190th pardouin 🇫🇷 848 71 126ms 2 Sep 2024 191st edsrzf 🇳🇿 848 91 5ms 42 hours ago 192nd JayXon 🇺🇸 847 68 75ms 18 Jun 2025 193rd error256 846 94 108ms 1 Sep 2024 194th JayXon 🇺🇸 846 95 99ms 24 May 2025 195th CLOStrophobic 🇮🇹 846 108 6ms 19 Feb 2025 196th xsot 🇸🇬 844 50 37ms 12 hours ago 197th retrohun 844 99 506ms 11 days ago 198th HumanoidCPU 843 74 12ms 2 Sep 2024 198th sean-niemann 🇺🇸 843 74 5ms 19 Dec 2024 198th luuumine 🇫🇷 843 74 11ms 15 Oct 2025 201st GrayJoKing 🇦🇺 843 84 9ms 2 Sep 2024 201st uttumuttu 🇫🇮 843 84 9ms 30 Sep 2024 201st didion0 🇺🇸 843 84 9ms 30 May 2025 204th edsrzf 🇳🇿 843 125 45ms 31 Dec 2024 204th kg583 🇺🇸 843 125 43ms 25 Mar 2025 206th SirBogman 🇺🇸 841 36 33ms 11 Sep 2024 207th bizy-coder 841 69 482ms 3 Sep 2024 208th Kacarott 🇦🇺 841 89 68ms 1 Sep 2024 208th error256 841 89 63ms 9 days ago 210th rhdqor213 840 107 2ms 12 days ago 211th sean-niemann 🇺🇸 839 62 696ms 22 Sep 2025 212th AlephSquirrel 839 109 6ms 18 Feb 2025 213th Shanethegamer 🇺🇸 838 96 98ms 24 May 2025 214th Shanethegamer 🇺🇸 836 202 1,426ms 1 Mar 2025 215th xnor-gate 834 82 14ms 5 Mar 2025 216th nwellnhof 🇩🇪 833 48 4ms 1 Sep 2024 217th MeWhenI 🇻🇦 832 75 5ms 3 Sep 2024 217th Artemis21 🇬🇧 832 75 10ms 10 Jan 2025 217th xsot 🇸🇬 832 75 5ms 2 days ago 220th nwellnhof 🇩🇪 832 108 2ms 10 Sep 2024 221st JayXon 🇺🇸 831 111 379ms 20 Sep 2024 222nd MeWhenI 🇻🇦 830 45 3ms 1 Sep 2024 223rd MeWhenI 🇻🇦 830 55 875ms 1 Sep 2024 223rd Natanaelel 🇸🇪 830 55 858ms 1 Sep 2024 225th Shanethegamer 🇺🇸 830 145 1,289ms 4 Sep 2024 225th m-tkach 🇺🇦 830 145 81ms 27 Sep 2024 227th HumanoidCPU 829 70 358ms 2 Sep 2024 228th MeWhenI 🇻🇦 829 75 4,629ms 24 Oct 2024 228th duckyluuk 🇳🇱 829 75 3,884ms 25 Oct 2024 230th emgordon154 825 59 10ms 15 Nov 2024 231st error256 825 63 964ms 8 hours ago 232nd error256 825 146 1,371ms 2 May 2025 233rd emplv 🇱🇻 824 159 251ms 18 Sep 2024 234th duckyluuk 🇳🇱 823 86 9ms 1 Sep 2024 235th sean-niemann 🇺🇸 823 112 385ms 4 Sep 2024 236th o0BlackDragon0o 821 76 13ms 8 Sep 2024 236th Bombalech 821 76 12ms 8 Sep 2024 236th JunkIce 821 76 14ms 24 Nov 2024 239th MeWhenI 🇻🇦 821 98 407ms 2 Sep 2024 240th rak1507 🇬🇧 819 31 3ms 11 Sep 2024 First Prev 161–240 of 710 Next Last