The Calendar hole will go live in approximately 4 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 561st stefangimmillaro 698 193 3,962ms 12 Nov 2024 562nd stefangimmillaro 698 262 264ms 5 May 2025 562nd edsrzf 🇳🇿 698 262 271ms 10 Jun 2025 564th Sp3000 🇦🇺 693 41 4ms 19 Jan 2024 564th MeWhenI 🇻🇦 693 41 5ms 2 Mar 2025 566th KingSkyrock 🇺🇸 692 106 10ms 17 Mar 2022 567th ian-h-chamberlain 🇺🇸 692 270 208ms 13 Nov 2025 568th lifthrasiir 🇰🇷 691 50 3ms 28 Nov 2024 569th KatieLG 🇬🇧 691 96 430ms 28 Oct 2024 570th CaedenHarper 🇨🇦 690 231 448ms 5 Oct 2025 571st emgordon154 689 118 1,078ms 3 Dec 2024 572nd Shanethegamer 🇺🇸 688 58 40ms 13 Feb 2022 572nd SirBogman 🇺🇸 688 58 42ms 10 Jan 2024 574th Ripick 688 186 352ms 24 Jun 2025 575th edsrzf 🇳🇿 686 38 4ms 14 Oct 2025 576th MathisBullinger 685 107 10ms 11 May 2022 576th CaedenHarper 🇨🇦 685 107 10ms 23 Aug 2025 578th iakolzin 684 205 61ms 1 Jul 2022 579th nwellnhof 🇩🇪 683 110 475ms 24 May 2022 579th AlephSquirrel 683 110 264ms 29 May 2023 579th 5cw 🇺🇸 683 110 259ms 9 May 2024 579th Seek64 🇩🇪 683 110 387ms 13 Sep 2024 583rd CatsAreFluffy 681 206 68ms 24 Feb 2023 584th revlayle 🇺🇸 680 201 325ms 9 Dec 2022 585th janbehrens 🇩🇪 678 199 491ms 26 Mar 2022 586th roavin 677 202 335ms 30 Jun 2022 587th shinh 676 59 47ms 21 Jun 2022 587th lacrosse 676 59 131ms 14 days ago 589th 386asm 🇺🇸 675 222 43ms 5 May 2023 590th randolchance 673 109 10ms 4 Jan 2024 591st edsrzf 🇳🇿 673 124 5ms 6 Oct 2025 592nd Mikey-Beep 🇬🇧 673 203 369ms 2 Sep 2024 592nd tomh1012 673 203 359ms 5 Sep 2025 594th MeWhenI 🇻🇦 671 112 209ms 22 May 2024 595th MeWhenI 🇻🇦 670 146 6ms 13 Aug 2024 596th prestosilver 🇺🇸 670 174 1ms 18 Nov 2025 597th Natanaelel 🇸🇪 668 86 34ms 29 Jan 2024 598th janbehrens 🇩🇪 667 6 44ms 25 Nov 2022 599th alemelis 666 101 812ms 26 Aug 2024 600th Shanethegamer 🇺🇸 665 61 5ms 13 Feb 2022 601st xnor-gate 665 113 35ms 14 Feb 2022 602nd Garklein 🇨🇦 664 52 3ms 13 Feb 2022 602nd Natanaelel 🇸🇪 664 52 2ms 14 Jul 2023 602nd SirBogman 🇺🇸 664 52 2ms 6 Nov 2023 605th janbehrens 🇩🇪 663 206 329ms 26 Feb 2022 606th oeb25 663 282 207ms 16 May 2022 607th two-bad 🇬🇧 661 111 9ms 25 Feb 2024 608th Shanethegamer 🇺🇸 661 122 7ms 12 Apr 2024 609th billings7 🇬🇧 660 207 334ms 16 Apr 2022 610th jmerle 🇳🇱 659 114 16ms 15 Feb 2023 611th edsrzf 🇳🇿 659 182 106ms 26 days ago 612th jgbaldwinbrown 658 177 2ms 15 Jun 2022 613th IISResetMe 657 88 396ms 40 hours ago 614th m-tkach 🇺🇦 657 101 417ms 21 Jan 2024 615th edsrzf 🇳🇿 657 282 5ms 20 Feb 2025 616th rniii 654 61 43ms 15 Sep 2023 616th olleicua 🇺🇸 654 61 42ms 6 Jan 2024 616th anter69 🇭🇺 654 61 71ms 2 Apr 2024 616th xsot 🇸🇬 654 61 40ms 23 Apr 2025 616th beirigo 🇧🇷 654 61 40ms 17 Oct 2025 621st CatsAreFluffy 654 178 2ms 24 Feb 2023 622nd Salutations45 653 96 2ms 22 Jan 2025 623rd lynn 653 115 16ms 12 Feb 2022 623rd Kacarott 🇦🇺 653 115 559ms 4 Feb 2025 625th MeWhenI 🇻🇦 653 204 2ms 11 Sep 2022 626th jerrandolph 653 280 266ms 19 Dec 2023 627th Florian-Mt 653 286 288ms 15 Jul 2024 628th albanian-laundromat 652 40 4ms 17 days ago 629th UnderKoen 🇳🇱 652 284 12ms 26 Aug 2025 630th TehFlaminTaco 649 113 28ms 10 Nov 2022 631st thehylian 648 116 15ms 14 Jan 2023 631st zacjl 648 116 16ms 20 Apr 2023 633rd Shanethegamer 🇺🇸 648 151 19ms 14 Aug 2024 634th CatsAreFluffy 646 205 142ms 31 Mar 2023 635th SirBogman 🇺🇸 646 283 41ms 31 Dec 2023 636th CaedenHarper 🇨🇦 645 212 372ms 17 Oct 2025 637th nwellnhof 🇩🇪 644 62 40ms 4 Jun 2022 637th KL-Lru 644 62 40ms 29 Dec 2022 637th Natanaelel 🇸🇪 644 62 40ms 9 Dec 2023 637th KatieLG 🇬🇧 644 62 47ms 2 Oct 2025 First Prev 561–640 of 1,156 Next Last