The Calendar hole will go live in approximately 7 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 641st betaveros 642 117 16ms 31 Dec 2022 641st DayDun 🇸🇪 642 117 21ms 22 Jan 2023 641st KasperKivimaeki 🇫🇮 642 117 14ms 1 Jul 2025 641st bzijlema 🇳🇱 642 117 16ms 12 Nov 2025 645th ovs-code 🇩🇪 640 105 1,160ms 27 Oct 2023 646th jupj 🇫🇮 640 182 2ms 16 Sep 2022 646th jared-hughes 640 182 2ms 9 Jan 2023 648th Yewzir 🇧🇪 639 211 492ms 9 Feb 2023 649th MiffOttah 639 214 407ms 28 Nov 2024 650th Florian-Mt 637 115 10ms 27 Oct 2023 651st bizy-coder 637 118 38ms 6 Aug 2023 651st Rubiksmath 637 118 40ms 7 Aug 2023 651st StefanHabel 🇨🇦 637 118 15ms 4 Sep 2023 654th NickTheEASDude 🇺🇸 637 154 3ms 18 Sep 2024 655th DialFrost 🇸🇬 637 287 258ms 29 May 2025 656th IISResetMe 636 91 348ms 27 days ago 657th edsrzf 🇳🇿 634 175 101ms 10 Jun 2025 658th jared-hughes 634 221 2,403ms 9 Jan 2023 659th Frowny 631 119 179ms 13 Feb 2022 659th prplz 🇦🇺 631 119 17ms 13 Feb 2022 659th bricknellj 631 119 20ms 14 Feb 2023 659th edsrzf 🇳🇿 631 119 22ms 4 Oct 2025 659th Natanaelel 🇸🇪 631 119 16ms 13 Nov 2025 664th GolfingSuccess 🇬🇷 631 163 120ms 29 Jul 2025 665th emgordon154 629 93 120ms 7 Aug 2024 666th Yewzir 🇧🇪 629 397 2,450ms 15 Nov 2025 667th stefangimmillaro 628 133 5ms 2 Jul 2023 668th dokutan 627 190 141ms 12 Jul 2024 669th TobyBoyne 🇬🇧 626 120 16ms 18 Feb 2022 669th OllieBoyne 🇬🇧 626 120 15ms 18 Feb 2022 669th petroselo 626 120 190ms 12 Apr 2022 669th inventshah 626 120 15ms 15 Nov 2022 669th CaedenHarper 🇨🇦 626 120 17ms 27 Dec 2024 674th JRaspass 🇬🇧 626 292 299ms 18 May 2022 675th SirBogman 🇺🇸 625 92 34ms 23 Apr 2022 676th ChiefChippy2 624 64 34ms 12 Feb 2022 676th GrayJoKing 🇦🇺 624 64 38ms 13 Feb 2022 678th MeWhenI 🇻🇦 623 108 427ms 15 Feb 2023 679th targrik 623 134 5ms 14 Aug 2025 680th ovs-code 🇩🇪 622 94 136ms 17 Apr 2025 680th rucin93 🇵🇱 622 94 136ms 13 Jun 2025 682nd primo-ppcg 🇹🇭 621 121 20ms 4 Mar 2022 682nd EnTerr 621 121 22ms 8 Sep 2024 682nd Bulmenisaurus 621 121 12ms 3 Oct 2025 682nd ryyyn 🇺🇸 621 121 16ms 28 Oct 2025 686th Beariish 621 158 3ms 27 Mar 2025 687th elPossenreisser 621 220 358ms 6 May 2022 688th madex 🇩🇪 620 188 1ms 10 Apr 2022 689th Shanethegamer 🇺🇸 617 184 42ms 6 Sep 2024 690th ahmetdemirag 🇨🇾 616 122 14ms 15 Jul 2024 690th Lv0Sys 🇵🇱 616 122 23ms 18 days ago 692nd emgordon154 616 219 703ms 28 May 2025 693rd annaproxy 616 222 347ms 29 Mar 2022 694th janAkali 🇷🇺 615 208 349ms 9 Oct 2024 695th olivermrose 🇺🇸 614 65 37ms 15 Apr 2022 696th sean-niemann 🇺🇸 614 102 2ms 6 Jun 2023 697th AlephSquirrel 614 108 745ms 21 Jan 2024 698th adlerzei 613 223 353ms 5 May 2022 699th GolfingSuccess 🇬🇷 612 196 116ms 26 days ago 700th efgen 611 120 11ms 28 Dec 2023 701st jared-hughes 611 123 16ms 8 Sep 2022 701st quimey 611 123 17ms 4 Jul 2023 701st htareque 611 123 11ms 17 Oct 2023 704th wackbyte 611 306 250ms 7 Dec 2023 705th msbranicky 609 300 287ms 31 Aug 2023 706th scpchicken 🇵🇼 605 66 38ms 13 Feb 2022 707th Shanethegamer 🇺🇸 604 232 2,483ms 16 Feb 2022 708th bizy-coder 603 110 423ms 16 Jan 2024 708th MeWhenI 🇻🇦 603 110 592ms 24 May 2024 708th CaedenHarper 🇨🇦 603 110 450ms 27 Dec 2024 711th emgordon154 603 310 259ms 6 Mar 2025 712th RockOfStone 602 163 2ms 14 Mar 2024 713th bac0id 602 233 66ms 27 Jun 2024 714th RYNO8 601 125 16ms 16 Aug 2022 715th MeWhenI 🇻🇦 600 174 5ms 15 Oct 2023 716th emgordon154 600 414 481ms 4 Oct 2025 717th RobertHoeh 599 225 3,109ms 5 days ago 718th janbehrens 🇩🇪 599 266 467ms 26 Feb 2022 718th cbrt-x 599 266 428ms 6 May 2022 720th GrayJoKing 🇦🇺 596 98 131ms 11 Aug 2024 First Prev 641–720 of 1,154 Next Last