The Calendar hole will go live in approximately 12 days. Why not try and solve it ahead of time?
Pernicious Numbers (Long) 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 799th tayloia 🇬🇧 724 61 11ms 9 Jan 2023 799th iczelia 🇩🇪 724 61 12ms 5 Nov 2025 803rd Yewzir 🇧🇪 724 123 269ms 12 Feb 2024 803rd MeWhenI 🇻🇦 724 123 274ms 9 Apr 2024 805th jhpaques 🇫🇷 723 70 18ms 30 Nov 2022 805th michelebastione 🇮🇹 723 70 17ms 7 Dec 2022 805th Skwerl23 723 70 22ms 5 Feb 2023 805th celiendonze 🇨🇭 723 70 17ms 21 Apr 2023 805th epic-programmer-guy 723 70 17ms 20 Dec 2023 805th Stockoh 🇫🇷 723 70 267ms 24 Apr 2024 805th CutSandstone 723 70 16ms 5 Jul 2024 805th Andrey135296 723 70 16ms 25 Oct 2024 805th Emutis 🇱🇹 723 70 19ms 27 Oct 2024 814th primo-ppcg 🇹🇭 721 43 352ms 20 Nov 2022 815th snoozingnewt 🇨🇦 720 68 119ms 8 Oct 2023 815th rboath 720 68 2,066ms 11 Dec 2024 817th Alex-x90 🇺🇸 718 75 4ms 20 Nov 2022 817th Irratix 🇳🇱 718 75 4ms 14 Jan 2023 817th Vinterion 718 75 4ms 19 Jul 2024 820th prplz 🇦🇺 718 86 243ms 16 Jan 2023 821st msbranicky 718 124 272ms 3 Oct 2023 822nd MeWhenI 🇻🇦 715 36 421ms 30 Dec 2023 823rd dokutan 715 72 2,687ms 4 days ago 824th edsrzf 🇳🇿 715 82 29ms 9 Sep 2025 825th syntax-rules 714 75 52ms 15 May 2023 826th Alex-x90 🇺🇸 713 62 12ms 14 Jan 2023 826th m-tkach 🇺🇦 713 62 13ms 20 Mar 2023 826th emgordon154 713 62 12ms 19 Mar 2025 826th Yax42 🇫🇷 713 62 11ms 6 Sep 2025 830th Fishron 713 71 17ms 29 Nov 2022 830th wobblybits 713 71 19ms 29 Aug 2025 832nd inventshah 712 64 137ms 4 Aug 2024 833rd 4hg 🇺🇸 710 58 54ms 11 Dec 2022 833rd csharpython 710 58 62ms 5 Aug 2025 835th brimstonetrader 710 87 282ms 24 Dec 2023 836th RYNO8 709 76 3ms 20 Aug 2023 837th sean-niemann 🇺🇸 709 87 46ms 21 Apr 2023 838th msbranicky 708 161 1,703ms 16 Sep 2025 839th dokutan 706 34 37ms 21 Aug 2024 840th CaedenHarper 🇨🇦 705 99 513ms 3 Oct 2025 841st masflam 704 59 431ms 21 Jun 2024 842nd mbittner20 703 72 17ms 27 May 2023 842nd eiburns 703 72 19ms 27 Oct 2023 842nd WillowWispy 703 72 17ms 14 Mar 2025 845th yzhs 🇩🇪 702 88 195ms 26 Jun 2023 846th Yewzir 🇧🇪 701 80 100ms 12 Feb 2024 847th Steffan153 🇫🇮 700 66 20ms 14 Feb 2024 848th dokutan 700 71 43ms 18 Nov 2025 849th tatzyr 🇯🇵 698 59 55ms 17 Nov 2024 849th ejini6969 698 59 59ms 14 Jun 2025 851st janbehrens 🇩🇪 698 92 364ms 17 Apr 2025 851st MeWhenI 🇻🇦 698 92 385ms 19 Jun 2025 853rd Shanethegamer 🇺🇸 696 77 55ms 30 Nov 2022 854th msbranicky 693 60 454ms 15 Jan 2024 854th alemelis 693 60 539ms 29 Aug 2024 856th MeWhenI 🇻🇦 693 100 434ms 9 Apr 2024 857th Florian-Mt 692 99 131ms 12 Jul 2024 858th Steffan153 🇫🇮 691 74 10ms 20 Nov 2022 859th MeWhenI 🇻🇦 691 78 4ms 9 Apr 2024 860th dokutan 691 129 315ms 10 Mar 2025 861st voytxt 🇨🇿 690 64 15ms 21 Jul 2023 862nd prplz 🇦🇺 685 113 30ms 31 Dec 2022 863rd CaedenHarper 🇨🇦 685 130 244ms 3 Dec 2024 864th Anthony-Williams-06 684 74 17ms 12 Sep 2024 865th steffan-polygolf 684 77 80ms 24 Feb 2023 866th annaproxy 683 94 356ms 22 Oct 2023 867th janbehrens 🇩🇪 682 79 4ms 20 Nov 2022 867th weliveinhell 🇭🇹 682 79 4ms 21 May 2024 869th Yewzir 🇧🇪 681 73 40ms 24 Feb 2024 870th weliveinhell 🇭🇹 680 65 12ms 15 Sep 2023 870th dylanarmstrong 680 65 12ms 25 Jan 2024 870th Yewzir 🇧🇪 680 65 14ms 12 Feb 2024 873rd Yewzir 🇧🇪 680 69 6ms 13 Feb 2024 874th snoozingnewt 🇨🇦 680 102 417ms 9 Oct 2025 875th kkoenig 680 131 282ms 2 Jan 2024 876th snoozingnewt 🇨🇦 679 52 4ms 9 Oct 2025 877th MeWhenI 🇻🇦 679 77 94ms 9 Apr 2024 878th MeWhenI 🇻🇦 679 92 45ms 14 Feb 2025 878th AlephSquirrel 679 92 48ms 21 Mar 2025 880th msbranicky 678 76 4,767ms 6 Jan 2025 First Prev 801–880 of 1,816 Next Last