The Calendar hole will go live in approximately 9 days. Why not try and solve it ahead of time?
All holes in Ruby 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 Holes Points Bytes Submitted 561st rtmacaibay 1 602 83 28 Mar 2020 562nd p-vf 🇨🇭 1 600 55 25 Oct 2021 563rd genius257 1 595 84 29 Mar 2018 563rd joesenova 1 595 84 26 Apr 2018 565th youchan 1 588 85 16 Dec 2018 566th basuneko 1 587 46 8 Nov 2017 567th alexandre-lavoie 1 581 86 30 Jul 2020 567th kjeldahl 1 581 86 4 Nov 2020 567th ratPoopert 1 581 86 31 Jan 2023 570th julioolvr 1 575 87 1 Aug 2020 570th 5si 1 575 87 2 Nov 2020 572nd Mikaeel66 1 574 47 10 Nov 2019 572nd Edjyzod 1 574 47 3 Oct 2022 574th lightgeb 2 571 474 27 Oct 2023 575th neihousaigaai 1 570 93 13 Feb 2024 576th martica 1 568 44 20 May 2018 577th Marcel-Brouette 1 563 48 26 Aug 2018 578th etzrxd 1 562 153 25 Aug 2023 579th ashtraypettingzoo 🇺🇸 1 556 45 16 Feb 2023 579th hacker112 🇸🇪 1 556 45 1 Jul 2024 581st alexkurowski 1 551 49 8 Nov 2017 582nd ngocbd 🇻🇳 1 549 71 31 Aug 2021 583rd BuoyantPigeon 1 543 92 10 Aug 2019 584th jthorup84 1 541 109 22 Nov 2017 585th sstadick 1 540 50 24 Jan 2018 586th kenakingkong 1 540 63 4 May 2021 587th Import-Meow 2 536 330 31 May 2022 588th JesseNoEyes 🇺🇸 1 532 47 26 Sep 2024 588th Mikey-Beep 🇬🇧 1 532 47 20 Aug 2025 590th Krtecik 1 529 51 9 Feb 2024 591st Schmitt-Very-Cool 3 529 1,434 18 Jul 2024 592nd PotatoSaladOverlord 1 526 95 18 Jan 2024 593rd hyvyys 1 525 59 22 Sep 2020 594th vcxl-l 1 522 67 21 Aug 2024 595th sech1p 🇵🇱 1 521 48 30 Dec 2020 595th martinnorling 🇸🇪 1 521 48 6 Feb 2022 595th eiburns 1 521 48 7 Sep 2023 595th SwordF-Official 1 521 48 2 Jun 2025 599th artem-aramma 1 518 83 18 Jun 2025 600th serene 1 515 97 12 May 2023 601st jansekulowicz 1 512 82 8 May 2022 602nd b-paul 1 510 49 25 Dec 2020 603rd hiracky16 1 508 61 15 Dec 2019 604th juntuu 1 508 65 24 Mar 2019 605th Mefred 1 506 87 26 days ago 606th vonKrafft 2 500 106 26 Mar 2020 607th takafan 🇨🇳 1 497 155 13 Sep 2023 608th gotbadger 1 494 233 21 Nov 2024 609th ze-h 🇺🇸 1 492 63 18 May 2022 610th andymac-2 1 492 195 7 Jul 2024 611th DNNX 1 491 55 3 Jan 2020 612th kittrz9 5 491 4,212 7 Dec 2017 613th azure-blondon 1 490 51 10 Jul 2024 614th Dominoscompute 1 490 102 18 Jul 2022 615th ferblape 1 483 116 26 Dec 2020 616th LHLaurini 🇧🇷 1 483 528 14 Jul 2024 617th gpolumbo-broad 1 481 52 14 Mar 2019 618th ArturLukianov 1 481 104 17 Dec 2020 618th abbasmoosajee07 1 481 104 25 May 2025 620th Ripick 1 477 65 17 Mar 2024 621st Adix-null 🇱🇹 2 477 1,065 1 Aug 2023 622nd j-Ewan 1 476 105 15 Feb 2022 623rd axpepper 1 473 93 29 Sep 2018 624th GWStuart 2 473 1,124 15 Sep 2023 625th uncertaain 1 472 89 4 Dec 2024 626th pengu1n-master 1 472 106 11 Dec 2021 626th copoer 1 472 106 28 Feb 2023 626th keelimeguy 🇺🇸 1 472 106 24 Oct 2023 629th Drew-j-Smith 1 467 75 11 Jan 2023 630th johnreitano 1 467 422 21 Dec 2022 631st mothcolada 🇺🇸 8 466 7,142 26 May 2021 632nd MaxElf999 1 463 67 14 Dec 2022 633rd kkittlive 1 463 108 5 Oct 2020 634th twocatsinatrenchcoat 1 459 109 25 Apr 2022 635th Smetalo 1 458 72 25 Aug 2022 636th Msleizak 🇫🇷 3 454 2,187 14 Dec 2023 637th kurkale6ka 5 448 4,101 7 days ago 638th Lucca-mito 1 446 112 18 Apr 2018 639th Nekall 1 444 126 2 Jun 2022 640th markturner 1 440 75 30 Nov 2020 First Prev 561–640 of 810 Next Last