The Calendar hole will go live in approximately 13 days. Why not try and solve it ahead of time?
Reverse Polish Notation in Ruby 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 1st Lydxn 🇨🇦 1,000 44 76ms 21 Aug 2022 2nd sisyphus-ppcg 🇦🇺 936 47 42ms 18 Feb 2022 3rd akshatj27 🇦🇶 830 53 54ms 14 Feb 2022 3rd MeWhenI 🇻🇦 830 53 75ms 25 Jul 2023 3rd Steffan153 🇫🇮 830 53 49ms 20 Aug 2024 3rd radarek 🇵🇱 830 53 96ms 27 Dec 2024 7th primo-ppcg 🇹🇭 815 54 37ms 14 Feb 2022 7th janlelis 815 54 95ms 21 Sep 2024 7th ovs-code 🇩🇪 815 54 40ms 27 Dec 2024 7th sean-niemann 🇺🇸 815 54 55ms 3 Aug 2025 11th JayXon 🇺🇸 786 56 40ms 23 Feb 2025 11th pardouin 🇫🇷 786 56 72ms 12 Sep 2025 13th stefangimmillaro 772 57 37ms 18 Feb 2022 13th tatzyr 🇯🇵 772 57 42ms 26 Feb 2025 15th Shanethegamer 🇺🇸 759 58 36ms 13 Feb 2022 15th SirBogman 🇺🇸 759 58 40ms 10 Jan 2024 17th shinh 746 59 39ms 21 Jun 2022 17th lacrosse 746 59 54ms 5 days ago 19th rniii 721 61 40ms 15 Sep 2023 19th olleicua 🇺🇸 721 61 42ms 6 Jan 2024 19th anter69 🇭🇺 721 61 67ms 2 Apr 2024 19th xsot 🇸🇬 721 61 39ms 23 Apr 2025 19th beirigo 🇧🇷 721 61 53ms 17 Oct 2025 24th nwellnhof 🇩🇪 710 62 38ms 4 Jun 2022 24th KL-Lru 710 62 39ms 29 Dec 2022 24th Natanaelel 🇸🇪 710 62 40ms 9 Dec 2023 24th KatieLG 🇬🇧 710 62 53ms 2 Oct 2025 28th ChiefChippy2 688 64 34ms 12 Feb 2022 28th GrayJoKing 🇦🇺 688 64 40ms 13 Feb 2022 30th olivermrose 🇺🇸 677 65 42ms 15 Apr 2022 31st scpchicken 🇵🇼 667 66 38ms 13 Feb 2022 32nd adoxography 647 68 35ms 20 Mar 2022 33rd jared-hughes 638 69 36ms 10 Sep 2022 34th edsrzf 🇳🇿 629 70 38ms 4 Sep 2025 35th emgordon154 611 72 38ms 20 Nov 2024 35th Lv0Sys 🇵🇱 611 72 54ms 12 days ago 37th m-tkach 🇺🇦 595 74 49ms 25 Jun 2024 38th DialFrost 🇸🇬 571 77 34ms 25 Dec 2024 39th rucin93 🇵🇱 557 79 45ms 31 May 2025 40th CaedenHarper 🇨🇦 537 82 36ms 13 Sep 2025 41st akiratee 506 87 40ms 20 Oct 2025 42nd annaproxy 494 89 33ms 14 Sep 2023 43rd aksyristos 489 90 32ms 8 Feb 2023 44th truisseaux 130 338 45ms 12 Apr 2024 45th KatieLG-Transpiler 🇬🇧 48 909 33ms 5 Jan 2023 1–45 of 45