The Calendar hole will go live in approximately 13 days. Why not try and solve it ahead of time?
Reverse Polish Notation in all languages 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 801st GolfingSuccess 🇬🇷 549 114 2ms 16 Oct 2024 802nd KatieLG 🇬🇧 548 74 5ms 19 Mar 2022 803rd nstearns96 🇬🇧 548 137 24ms 15 Dec 2022 803rd mossprescott 548 137 11ms 19 Jan 2023 803rd taesungh 548 137 16ms 15 Oct 2023 803rd PyryL 🇫🇮 548 137 18ms 25 Aug 2024 807th stellartux 547 123 584ms 24 Dec 2023 808th zakariamouhid 547 134 10ms 11 May 2023 809th michelebastione 🇮🇹 544 138 16ms 19 Feb 2022 809th knutae 🇳🇴 544 138 15ms 8 Mar 2022 809th RDShah 544 138 32ms 15 May 2022 809th ImpressedByRocks 544 138 16ms 10 Oct 2024 813th c0d3-4-F00d 🇩🇪 544 214 2ms 24 Feb 2022 814th codewrite 🇬🇧 542 252 380ms 13 May 2025 815th MeWhenI 🇻🇦 540 64 2ms 15 Feb 2022 816th Shanethegamer 🇺🇸 540 116 2ms 5 Nov 2022 817th cefqrn 540 139 17ms 20 Dec 2022 817th alfonsoalves 540 139 17ms 1 Mar 2024 817th hiichbindermax 540 139 37ms 19 Sep 2024 817th jacekwladzinski 540 139 11ms 10 Oct 2025 821st m-tkach 🇺🇦 539 74 49ms 25 Jun 2024 822nd hjcafaroUC 539 260 3,154ms 20 Aug 2022 823rd Bmrl7 537 140 24ms 9 Mar 2024 824th bac0id 537 217 1ms 27 Jun 2024 825th snoozingnewt 🇨🇦 534 253 107ms 8 Oct 2025 826th MeWhenI 🇻🇦 533 76 5ms 16 Apr 2023 827th SirFireball3521 533 141 37ms 7 Feb 2023 827th AstroOrbis 533 141 15ms 12 Jul 2025 827th RaBa21 🇭🇺 533 141 10ms 14 Jul 2025 830th MeWhenI 🇻🇦 533 208 99ms 16 Oct 2022 831st neel11235813 531 125 434ms 17 Mar 2024 832nd IlkkaTakala 531 264 2,747ms 20 Dec 2023 833rd KatieLG 🇬🇧 531 470 1,882ms 27 days ago 834th codewrite 🇬🇧 530 345 266ms 16 Jun 2025 835th MichalMarsalek 🇨🇿 529 142 15ms 14 Feb 2022 835th marcin7Cd 529 142 15ms 20 Feb 2022 837th MeWhenI 🇻🇦 528 317 32ms 6 Jun 2023 838th varhammer 🇷🇺 526 196 5ms 13 Dec 2023 839th janbehrens 🇩🇪 525 128 1,867ms 23 Feb 2022 840th SniperSmiley 🇺🇸 525 143 15ms 8 Jul 2022 840th Europe2048 525 143 24ms 22 Oct 2024 840th moustave 525 143 11ms 7 Apr 2025 843rd MeWhenI 🇻🇦 523 139 787ms 15 Sep 2025 844th randolchance 522 144 20ms 4 Jan 2024 844th roupiq 🇵🇱 522 144 17ms 1 Mar 2024 844th robin-scragg 522 144 18ms 22 Aug 2025 844th Deppyforce 522 144 15ms 9 Nov 2025 848th warmCabin 522 223 2ms 15 Apr 2022 849th Shanethegamer 🇺🇸 520 224 2ms 28 May 2025 850th MeWhenI 🇻🇦 520 246 363ms 27 Jul 2024 851st postie77 520 263 336ms 19 May 2023 852nd MeWhenI 🇻🇦 519 255 150ms 13 Feb 2022 853rd ovs-code 🇩🇪 519 398 9ms 8 Jul 2024 854th DialFrost 🇸🇬 518 77 34ms 25 Dec 2024 855th LeeCamp 518 145 16ms 14 Feb 2022 855th hellwue 518 145 10ms 7 Feb 2023 855th adamnielson42 🇺🇸 518 145 25ms 8 Oct 2024 855th Mabeloid 🇳🇴 518 145 26ms 4 May 2025 855th te-chnical 518 145 16ms 9 Jul 2025 860th karhuthebear 514 146 16ms 6 May 2022 860th Bonjour27891 🇻🇳 514 146 11ms 17 Jul 2022 860th Player01osu 514 146 11ms 28 Oct 2023 863rd nephila-nacrea 🇬🇧 513 79 5ms 20 Feb 2022 864th Sciman101 512 192 2ms 27 Mar 2025 865th error256 511 51 3ms 6 May 2024 866th Bodo171 511 147 19ms 7 Dec 2022 866th vgamula 🇺🇦 511 147 15ms 6 Nov 2023 866th croc54 511 147 15ms 27 Jan 2025 869th dokutan 509 193 2ms 13 Jan 2025 870th MeWhenI 🇻🇦 509 367 202ms 15 Feb 2022 871st davecame 508 148 26ms 18 Sep 2023 872nd Yewzir 🇧🇪 505 63 69ms 11 Mar 2024 873rd rucin93 🇵🇱 505 79 45ms 31 May 2025 874th namcartoon06 504 278 2,720ms 30 Jun 2023 875th HumanoidCPU 503 132 372ms 29 Sep 2024 876th MeWhenI 🇻🇦 503 370 28ms 14 Feb 2022 877th adamnielson42 🇺🇸 502 146 9ms 2 Jun 2023 878th sleepyStick 501 150 15ms 15 Jul 2022 878th galloj 🇨🇿 501 150 18ms 9 Jan 2023 878th cingulataluke 501 150 12ms 27 Aug 2023 First Prev 801–880 of 1,153 Next Last