The Calendar hole will go live in approximately 13 days. Why not try and solve it ahead of time?
ISBN in all languages in bytes. 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 Bytes Time Submitted 877th bac0id 718 123 17ms 22 Sep 2023 877th HumanoidCPU 718 123 10ms 2 Mar 2025 877th Masttest 718 123 12ms 22 days ago 877th yujqiao 718 123 10ms 2 days ago 885th GeorgeStechman 🇬🇧 717 99 8ms 19 May 2022 885th vphoebe 717 99 9ms 25 May 2022 885th elisherer 🇮🇱 717 99 9ms 5 Jun 2022 888th revlayle 🇺🇸 716 108 364ms 20 Jan 2022 888th primo-ppcg 🇹🇭 716 108 334ms 20 Apr 2022 890th AlephSquirrel 715 136 3ms 14 May 2025 891st HallMatthew314 715 157 121ms 24 Jan 2022 892nd nullshallot 714 78 304ms 5 Jan 2025 893rd duckyluuk 🇳🇱 714 108 10ms 13 Dec 2024 894th Yewzir 🇧🇪 713 87 715ms 15 Nov 2025 895th pandapawskat 713 132 2ms 7 Feb 2022 896th dokutan 712 105 134ms 6 Jun 2025 897th HumanoidCPU 712 107 3,681ms 3 Mar 2025 898th Blendi-Goose 712 122 2ms 19 Jun 2025 899th Ailko 🇧🇪 712 124 11ms 6 May 2022 899th qwjhvbxi 712 124 10ms 10 Feb 2024 899th leon-w 712 124 11ms 24 Jul 2024 899th jbjd 712 124 16ms 12 Sep 2024 899th smilesformiles3 712 124 10ms 14 Jun 2025 904th albanian-laundromat 712 265 440ms 18 Oct 2025 905th jgbaldwinbrown 708 133 2ms 13 Oct 2022 905th klixel 🇨🇦 708 133 2ms 27 Nov 2023 907th TheZwierzLF 🇵🇱 707 108 502ms 25 days ago 908th MeWhenI 🇻🇦 706 123 1ms 2 Oct 2024 909th BenBanerjeeRichards 706 125 10ms 22 Apr 2022 909th richard-oelze 🇩🇪 706 125 9ms 8 May 2022 909th vishwathg 706 125 15ms 16 Sep 2022 909th Thonoton 706 125 16ms 24 Feb 2023 909th sandorstormen 706 125 16ms 11 Mar 2023 909th MiranDaniel 🇨🇿 706 125 16ms 28 Apr 2023 909th VictorStenvers 🇳🇱 706 125 17ms 26 Jun 2024 909th Terobero 706 125 16ms 3 Sep 2024 909th LostSyntax21 🇬🇧 706 125 16ms 9 Sep 2024 909th jamesthekee 706 125 10ms 22 Jan 2025 919th olleicua 🇺🇸 705 44 61ms 11 Mar 2024 920th jstanley0 705 77 44ms 5 Feb 2022 920th olivermrose 🇺🇸 705 77 52ms 5 Dec 2022 922nd jipsong 🇩🇪 705 116 72ms 25 Oct 2023 923rd fitzdotlol 🇺🇸 703 101 9ms 7 Mar 2022 923rd mrxz 🇳🇱 703 101 10ms 23 Jun 2024 925th snoozingnewt 🇨🇦 703 148 121ms 20 Nov 2025 926th Natanaelel 🇸🇪 702 62 32ms 21 Jun 2022 927th dokutan 701 84 1,214ms 14 Mar 2023 927th alemelis 701 84 868ms 21 Aug 2024 929th TetraPengwin 701 124 2ms 14 Mar 2025 930th TobyBoyne 🇬🇧 701 126 11ms 28 Jan 2022 930th OllieBoyne 🇬🇧 701 126 10ms 2 Mar 2022 930th Anonymousellama21 701 126 10ms 14 Apr 2022 930th Trunksistor 🇫🇷 701 126 11ms 19 Apr 2022 930th docd 701 126 16ms 8 Aug 2022 930th LogicalJoe 701 126 16ms 4 May 2023 930th pde-bakk 🇳🇱 701 126 10ms 23 Oct 2023 930th mstang107 701 126 10ms 20 Dec 2023 930th DGipe 701 126 9ms 13 May 2024 930th retrohun 701 126 9ms 18 Oct 2024 930th yokasuretsu 701 126 9ms 23 Jan 2025 930th bknower 701 126 10ms 26 Jun 2025 942nd inverseLorentz 🇦🇺 701 160 145ms 14 May 2024 943rd albanian-laundromat 701 192 24ms 12 days ago 944th albanian-laundromat 700 186 43ms 17 Nov 2025 945th msbranicky 700 190 262ms 3 Oct 2023 946th retrohun 697 75 2ms 9 Nov 2022 947th HumanoidCPU 697 158 91ms 3 Mar 2025 948th DialFrost 🇸🇬 696 84 5ms 14 Aug 2024 949th ShiraJoseph 🇺🇸 696 102 10ms 28 Jan 2023 949th itserasmus 696 102 9ms 17 Jan 2024 949th eranws 696 102 9ms 23 Dec 2024 952nd snoozingnewt 🇨🇦 696 119 100ms 13 days ago 953rd MeWhenI 🇻🇦 695 67 3ms 15 Apr 2023 954th jacklynnepenick 695 127 9ms 15 Feb 2022 954th Pena86 695 127 16ms 14 Sep 2022 954th pascscha 695 127 9ms 18 Sep 2022 954th DrPiranoid 695 127 10ms 8 Oct 2022 954th QuincyNash 🇺🇸 695 127 9ms 13 Nov 2022 954th epic-programmer-guy 695 127 10ms 21 Dec 2023 954th AdamMorris377 695 127 9ms 29 Jul 2024 First Prev 881–960 of 1,566 Next Last
