The Calendar hole will go live in approximately 12 days. Why not try and solve it ahead of time?
Card Number Validation 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 241st Kacarott 🇦🇺 801 73 1,117ms 1 Oct 2024 241st chunes3 🇺🇸 801 73 1,046ms 2 Oct 2024 243rd MeWhenI 🇻🇦 801 127 2ms 5 Oct 2024 243rd albanian-laundromat 801 127 3ms 3 Nov 2025 245th Shanethegamer 🇺🇸 801 208 1,488ms 14 Apr 2025 245th DialFrost 🇸🇬 801 208 521ms 18 Apr 2025 247th stefangimmillaro 800 89 417ms 4 Oct 2024 248th sean-niemann 🇺🇸 799 92 112ms 1 Oct 2025 249th snoozingnewt 🇨🇦 798 72 334ms 13 days ago 250th albanian-laundromat 797 74 765ms 3 Nov 2025 251st Babafaba 797 81 19ms 11 Nov 2025 252nd 2bular 796 49 31ms 8 Nov 2025 253rd tayloia 🇬🇧 795 81 9ms 3 Oct 2024 253rd targrik 795 81 9ms 8 Feb 2025 253rd Lv0Sys 🇵🇱 795 81 10ms 9 days ago 256th DialFrost 🇸🇬 795 85 6ms 1 Oct 2024 256th xsot 🇸🇬 795 85 5ms 7 Oct 2024 258th stefangimmillaro 794 87 99ms 4 Oct 2024 259th Shanethegamer 🇺🇸 794 102 384ms 4 Oct 2024 260th Shanethegamer 🇺🇸 794 128 2ms 3 Oct 2024 261st DialFrost 🇸🇬 793 84 4,106ms 26 Oct 2024 262nd albanian-laundromat 793 120 42ms 3 Nov 2025 263rd MeWhenI 🇻🇦 791 90 435ms 2 Oct 2024 264th MeWhenI 🇻🇦 791 109 394ms 2 Oct 2024 265th jared-hughes 791 203 101ms 20 Dec 2024 266th saito-ta 🇯🇵 790 74 7ms 1 Oct 2024 267th emgordon154 789 151 262ms 17 Jan 2025 268th Natanaelel 🇸🇪 788 48 212ms 1 Oct 2024 269th SB-945 788 82 16ms 1 Oct 2024 269th HumanoidCPU 788 82 61ms 7 Mar 2025 269th fkantelberg 788 82 11ms 11 Jul 2025 269th BrunoVisnadi 🇧🇷 788 82 10ms 21 Sep 2025 273rd KingSkyrock 🇺🇸 785 82 9ms 14 Oct 2024 274th Shanethegamer 🇺🇸 785 88 99ms 4 Oct 2024 275th kg583 🇺🇸 785 94 4ms 13 Nov 2025 276th SirBogman 🇺🇸 785 138 39ms 11 Jul 2025 277th edsrzf 🇳🇿 784 119 152ms 23 Jul 2025 277th namelessiw 784 119 440ms 9 Oct 2025 279th Shanethegamer 🇺🇸 784 152 264ms 3 Oct 2024 279th targrik 784 152 264ms 7 Jul 2025 281st stefangimmillaro 783 61 33ms 1 Oct 2024 282nd Shanethegamer 🇺🇸 782 91 416ms 3 Oct 2024 283rd SirBogman 🇺🇸 780 50 34ms 8 Jul 2025 284th ovs-code 🇩🇪 780 75 1,104ms 1 Oct 2024 285th MeWhenI 🇻🇦 780 122 39ms 5 Oct 2024 286th MeWhenI 🇻🇦 779 88 1ms 2 Oct 2024 287th sean-niemann 🇺🇸 779 107 332ms 3 Oct 2024 288th Bmrl7 778 83 10ms 3 Oct 2024 289th bizy-coder 777 74 461ms 1 Oct 2024 289th m-tkach 🇺🇦 777 74 474ms 3 Oct 2024 291st adriweb 🇫🇷 777 102 2ms 5 Oct 2024 292nd Shanethegamer 🇺🇸 777 120 454ms 24 Sep 2025 293rd emgordon154 777 166 1,626ms 2 Oct 2024 294th DialFrost 🇸🇬 776 76 745ms 30 Aug 2025 295th m-tkach 🇺🇦 776 131 3ms 4 Oct 2024 296th uttumuttu 🇫🇮 775 83 9ms 1 Oct 2024 296th KatieLG 🇬🇧 775 83 9ms 1 Oct 2024 296th Larento 775 83 9ms 4 Nov 2024 296th Andrey-Plotnikov 775 83 9ms 13 Jan 2025 296th nathanadams 🇳🇿 775 83 9ms 6 Oct 2025 301st duckyluuk 🇳🇱 775 97 9ms 24 days ago 302nd Natanaelel 🇸🇪 775 143 148ms 20 Apr 2025 303rd sean-niemann 🇺🇸 771 105 440ms 1 Oct 2024 304th DialFrost 🇸🇬 771 121 349ms 24 Sep 2025 305th sisyphus-ppcg 🇦🇺 770 62 59ms 3 Oct 2024 306th Waffle3z 770 103 1ms 2 Oct 2024 307th retrohun 769 63 25ms 2 Oct 2024 308th edsrzf 🇳🇿 769 76 1,005ms 1 Oct 2024 309th AlephSquirrel 769 84 19ms 1 Oct 2024 309th kops-cg 769 84 19ms 22 Feb 2025 309th xnor-gate 769 84 19ms 23 Feb 2025 309th plcc0 769 84 17ms 6 Apr 2025 309th KatieLG 🇬🇧 769 84 25ms 25 May 2025 314th DialFrost 🇸🇬 769 90 2ms 18 Nov 2025 315th targrik 768 88 8ms 7 Feb 2025 316th lifthrasiir 🇰🇷 767 37 2ms 27 Nov 2024 317th didion0 🇺🇸 766 84 9ms 10 Jan 2025 318th DialFrost 🇸🇬 766 131 7ms 11 Dec 2024 319th MeWhenI 🇻🇦 765 109 334ms 2 Oct 2024 319th edsrzf 🇳🇿 765 109 365ms 23 Jul 2025 First Prev 241–320 of 848 Next Last