The Calendar hole will go live in approximately 13 days. Why not try and solve it ahead of time?
Kolakoski Sequence 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 801st SnowballSH 707 71 11ms 12 Feb 2021 801st Andre3582 707 71 10ms 18 Mar 2021 801st PhysicDev 🇫🇷 707 71 11ms 20 May 2021 801st Alban-Boissard 707 71 12ms 10 Jun 2025 805th omurakazuaki 🇯🇵 706 66 9ms 18 Feb 2021 805th BambooleanLogic 🇸🇪 706 66 9ms 22 Aug 2022 805th coreynash 706 66 9ms 21 Oct 2023 805th two-bad 🇬🇧 706 66 9ms 24 Nov 2023 805th dylanarmstrong 706 66 9ms 15 Jan 2024 805th madeforlosers 706 66 9ms 5 Nov 2025 811th Stockoh 🇫🇷 706 68 357ms 24 Jun 2024 812th typeswitch-dev 🇵🇹 705 74 8ms 7 Aug 2023 813th msbranicky 704 65 1,074ms 12 Sep 2023 814th Shanethegamer 🇺🇸 704 91 39ms 16 Jun 2022 815th SnowballSH 703 60 44ms 12 Feb 2021 815th aksyristos 703 60 39ms 28 Feb 2023 815th Lv0Sys 🇵🇱 703 60 56ms 14 days ago 818th MeWhenI 🇻🇦 702 238 12ms 29 Aug 2023 819th MeWhenI 🇻🇦 701 35 49ms 26 Jul 2022 819th jared-hughes 701 35 44ms 31 Jul 2022 819th Natanaelel 🇸🇪 701 35 49ms 18 Aug 2022 822nd KasperKivimaeki 🇫🇮 701 125 260ms 3 Oct 2025 823rd UnderKoen 🇳🇱 700 134 12ms 20 Jan 2025 824th JayXon 🇺🇸 699 40 57ms 2 Jun 2021 825th jared-hughes 699 44 7ms 31 Jul 2022 826th Shanethegamer 🇺🇸 699 77 13ms 9 Oct 2023 827th JGDoerrer 699 103 474ms 5 Jan 2022 827th tailorspy 699 103 62ms 29 Oct 2023 829th LeeCamp 698 72 11ms 16 Feb 2022 829th LukasFolwarczny 🇨🇿 698 72 11ms 16 Sep 2022 829th CutSandstone 698 72 36ms 8 Jul 2024 832nd neihousaigaai 696 67 10ms 10 Apr 2021 833rd jared-hughes 696 159 1,670ms 16 Sep 2025 834th DialFrost 🇸🇬 695 56 84ms 22 Jul 2024 835th targrik 695 57 5ms 26 Aug 2025 836th boxjelly 694 94 114ms 21 Jan 2021 836th YAJUE114514 694 94 133ms 24 Jul 2025 838th dokutan 693 99 805ms 24 Sep 2025 839th Espiobest 691 61 37ms 13 Feb 2021 839th DaCuteRaccoon 691 61 40ms 9 Dec 2022 841st edsrzf 🇳🇿 691 91 19ms 21 Dec 2024 842nd MeWhenI 🇻🇦 691 106 341ms 26 Aug 2023 843rd Shanethegamer 🇺🇸 690 106 17ms 4 Oct 2024 844th msbranicky 689 95 5ms 11 Aug 2023 845th GolfingSuccess 🇬🇷 688 69 33ms 17 Aug 2024 846th richard-oelze 🇩🇪 688 73 29ms 4 Apr 2021 846th mauro-1 🇮🇹 688 73 9ms 18 Aug 2021 846th gchenfc 688 73 9ms 24 Jan 2022 846th hiichbindermax 688 73 11ms 26 Feb 2022 846th Omega65536 🇩🇪 688 73 11ms 24 Nov 2022 846th sandorstormen 688 73 11ms 18 Feb 2023 846th Mr-McChicken 688 73 11ms 15 Oct 2023 846th Masttest 688 73 10ms 21 Feb 2024 854th Andriamanitra 🇫🇮 687 95 148ms 20 Jul 2023 855th MeWhenI 🇻🇦 685 72 397ms 15 Feb 2023 855th Yewzir 🇧🇪 685 72 483ms 5 Apr 2024 857th msbranicky 685 89 1ms 26 Sep 2023 858th DialFrost 🇸🇬 684 67 131ms 3 Aug 2024 859th madex 🇩🇪 684 79 2ms 11 Jul 2024 860th AdrienHache 🇫🇷 682 41 50ms 23 Oct 2023 861st Yewzir 🇧🇪 681 90 327ms 14 Oct 2023 862nd jameslindesay 679 74 11ms 24 Feb 2021 862nd PkmnQ 679 74 37ms 5 May 2024 862nd HumanoidCPU 679 74 11ms 3 Jun 2024 862nd RedzGoose 🇦🇺 679 74 13ms 14 Oct 2024 862nd yokasuretsu 679 74 10ms 13 Jan 2025 867th I-Love-47 🇺🇦 679 106 63ms 10 Feb 2022 868th dokutan 678 59 3ms 18 Jul 2025 869th Shanethegamer 🇺🇸 678 126 24ms 8 Jul 2021 870th janbehrens 🇩🇪 673 68 1,067ms 9 Apr 2021 871st AdrienHache 🇫🇷 673 91 374ms 31 Dec 2023 872nd msbranicky 672 80 4ms 11 Oct 2023 873rd rboath 671 58 88ms 8 Jan 2025 874th 5quiwyrm 670 54 254ms 5 Dec 2024 875th Trunksistor 🇫🇷 670 75 10ms 25 May 2022 875th celiendonze 🇨🇭 670 75 11ms 16 Jun 2023 875th qwjhvbxi 670 75 10ms 9 Feb 2024 875th wenbang24 670 75 14ms 6 Apr 2024 879th tatzyr 🇯🇵 669 63 39ms 29 Dec 2024 880th CaedenHarper 🇨🇦 666 70 9ms 31 Jan 2025 First Prev 801–880 of 1,887 Next Last