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 321st ovs-code 🇩🇪 764 122 159ms 25 Apr 2025 322nd emplv 🇱🇻 763 76 130ms 29 Oct 2024 323rd albanian-laundromat 763 118 77ms 13 Nov 2025 324th GolfingSuccess 🇬🇷 762 70 6ms 6 Jun 2025 325th Shanethegamer 🇺🇸 761 132 7ms 2 Oct 2024 326th inventshah 760 85 18ms 4 Oct 2024 326th Artemis21 🇬🇧 760 85 10ms 10 Jan 2025 326th keelimeguy 🇺🇸 760 85 15ms 14 Jun 2025 329th MeWhenI 🇻🇦 759 89 5ms 2 Oct 2024 330th emgordon154 758 63 40ms 18 Nov 2024 330th SirBogman 🇺🇸 758 63 33ms 19 Jul 2025 332nd weliveinhell 🇭🇹 757 85 9ms 1 Oct 2024 332nd SteRoy 757 85 9ms 13 May 2025 334th AlephSquirrel 756 76 447ms 1 Oct 2024 335th 0xjac 🇨🇭 754 158 256ms 17 Jun 2025 336th GrayJoKing 🇦🇺 751 90 4ms 1 Oct 2024 337th stackofbears 750 52 35ms 14 Mar 2025 338th DialFrost 🇸🇬 749 75 1,019ms 10 Oct 2024 339th MeWhenI 🇻🇦 749 162 26ms 2 Oct 2024 340th Maznek 748 86 10ms 4 Oct 2024 341st MeWhenI 🇻🇦 748 89 4,060ms 24 Oct 2024 342nd MeWhenI 🇻🇦 748 106 1ms 2 Oct 2024 343rd rak1507 🇬🇧 747 38 2ms 30 Dec 2024 344th Babafaba 747 77 366ms 11 Nov 2025 345th Shanethegamer 🇺🇸 746 64 53ms 3 Oct 2024 345th Andriamanitra 🇫🇮 746 64 41ms 5 Oct 2024 347th luuumine 🇫🇷 745 92 1ms 14 days ago 347th bzd7 745 92 2ms 12 days ago 349th Shanethegamer 🇺🇸 744 121 83ms 3 Oct 2024 350th sean-niemann 🇺🇸 743 93 101ms 24 Oct 2024 351st sean-niemann 🇺🇸 743 116 469ms 24 Oct 2024 351st luuumine 🇫🇷 743 116 517ms 4 days ago 353rd SirBogman 🇺🇸 741 63 278ms 23 Jul 2025 354th GrayJoKing 🇦🇺 740 79 1,204ms 1 Oct 2024 355th KrausRaus 🇺🇸 740 87 9ms 1 Oct 2024 355th GeorgeStechman 🇬🇧 740 87 9ms 24 Oct 2024 355th coreynash 740 87 9ms 13 Feb 2025 355th kirjavascript 740 87 9ms 22 Jul 2025 359th Shanethegamer 🇺🇸 740 90 3,803ms 28 Oct 2024 359th ScottHamper 740 90 2,700ms 8 days ago 361st Shanethegamer 🇺🇸 740 156 30ms 2 Oct 2024 362nd HumanoidCPU 737 78 414ms 7 Mar 2025 363rd sean-niemann 🇺🇸 737 93 3ms 24 Oct 2024 364th MeWhenI 🇻🇦 736 111 117ms 2 Oct 2024 365th MeWhenI 🇻🇦 735 34 64ms 2 Oct 2024 365th emgordon154 735 34 63ms 11 Sep 2025 367th stefangimmillaro 735 92 9ms 2 Oct 2024 367th Shanethegamer 🇺🇸 735 92 5ms 3 Oct 2024 369th Shanethegamer 🇺🇸 735 100 116ms 24 May 2025 370th wh3n3v3r 🇨🇿 734 88 10ms 18 Nov 2024 371st Shanethegamer 🇺🇸 733 116 18ms 1 Oct 2024 372nd Shanethegamer 🇺🇸 731 101 4ms 2 Oct 2024 373rd error256 731 109 8ms 24 Jul 2025 374th stefangimmillaro 731 114 326ms 13 Oct 2024 375th anter69 🇭🇺 729 78 1,023ms 1 Oct 2024 376th stefangimmillaro 729 94 1ms 30 Oct 2024 377th Shanethegamer 🇺🇸 729 112 106ms 3 Oct 2024 378th CLOStrophobic 🇮🇹 728 160 40ms 27 Feb 2025 379th zacjl 724 110 6ms 10 Oct 2024 380th Shanethegamer 🇺🇸 724 126 1,275ms 2 Oct 2024 381st dtbao20 🇻🇳 723 89 10ms 1 Oct 2024 381st madeforlosers 723 89 8ms 17 Oct 2024 381st junkondo-jp 723 89 9ms 14 Dec 2024 384th annaproxy 723 132 14ms 1 Oct 2024 385th MeWhenI 🇻🇦 721 179 1,697ms 7 Nov 2025 386th weeble 720 74 6ms 1 Jul 2025 387th MeWhenI 🇻🇦 720 78 416ms 2 Oct 2024 388th Shanethegamer 🇺🇸 720 96 2ms 3 Oct 2024 389th nwellnhof 🇩🇪 718 90 18ms 1 Oct 2024 389th ovs-code 🇩🇪 718 90 15ms 3 Oct 2024 389th ryyyn 🇺🇸 718 90 19ms 26 Jul 2025 389th luuumine 🇫🇷 718 90 16ms 8 Oct 2025 389th JOrE20 🇺🇸 718 90 18ms 18 days ago 394th ovs-code 🇩🇪 716 81 122ms 17 Apr 2025 395th alexsave 715 90 9ms 28 Oct 2024 396th snyderek 🇺🇸 712 121 53ms 1 Oct 2024 397th h3ra993huskp 🇯🇵 712 131 497ms 19 days ago 398th rzv-me 711 95 5ms 5 Oct 2024 399th 5cw 🇺🇸 710 91 17ms 1 Oct 2024 399th stefangimmillaro 710 91 16ms 13 Oct 2024 First Prev 321–400 of 848 Next Last