The Calendar hole will go live in approximately 10 days. Why not try and solve it ahead of time?
PalindromemordnilaP in all languages 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 Points Bytes Time Submitted 641st MeWhenI 🇻🇦 497 181 2ms 13 Jun 2025 642nd HunterC14 494 155 10ms 21 Oct 2024 643rd madex 🇩🇪 491 183 2ms 2 Sep 2024 644th Naitzirch 🇳🇱 484 158 11ms 3 Jul 2025 645th alphafalfa 480 105 4ms 1 Nov 2024 646th snoozingnewt 🇨🇦 478 185 387ms 4 Oct 2025 647th snoozingnewt 🇨🇦 476 189 5ms 9 Oct 2025 648th rucin93 🇵🇱 476 251 221ms 5 Sep 2024 649th junkondo-jp 475 149 9ms 15 Dec 2024 650th KatieLG 🇬🇧 475 292 7ms 1 Sep 2024 651st janAkali 🇷🇺 470 171 385ms 17 May 2025 652nd DialFrost 🇸🇬 467 207 461ms 24 Sep 2025 653rd R4z0rX 466 152 9ms 1 Sep 2024 654th Apzyte-Gamer 464 165 10ms 28 Oct 2024 655th iczelia 🇩🇪 463 194 2ms 11 Oct 2025 656th two-bad 🇬🇧 454 156 9ms 4 Oct 2024 656th JOrE20 🇺🇸 454 156 9ms 20 days ago 658th CyberTapir 453 169 10ms 1 Sep 2024 659th snoozingnewt 🇨🇦 449 186 8ms 1 Sep 2024 660th msbranicky 445 269 217ms 1 Sep 2024 661st Shanethegamer 🇺🇸 438 115 2ms 1 Sep 2024 662nd rollershutter 435 176 10ms 18 Nov 2024 663rd ehulinsky 🇺🇸 432 122 3ms 3 Apr 2025 664th Yax42 🇫🇷 431 224 452ms 5 Oct 2025 665th Yewzir 🇧🇪 427 179 10ms 20 days ago 666th aksyristos 418 101 41ms 17 Nov 2024 667th MeWhenI 🇻🇦 411 260 94ms 13 Jun 2025 668th Jacob385 402 240 398ms 4 Sep 2024 669th bac0id 402 266 2,912ms 10 Jan 2025 670th zakariamouhid 398 178 10ms 14 Sep 2024 671st galloj 🇨🇿 396 101 10ms 4 Sep 2024 672nd varhammer 🇷🇺 389 235 8ms 20 Oct 2025 673rd Yewzir 🇧🇪 370 171 752ms 20 days ago 674th IISResetMe 366 127 359ms 17 Nov 2024 675th Giantnoodlemonster 365 246 2ms 27 Sep 2024 676th MeWhenI 🇻🇦 363 135 7ms 26 Sep 2024 677th Mikey-Beep 🇬🇧 354 193 14ms 13 Aug 2025 678th AidanWalter 346 221 11ms 3 Jan 2025 679th timhaj 🇸🇮 320 239 10ms 19 Sep 2024 680th snoozingnewt 🇨🇦 307 209 119ms 1 Sep 2024 681st nephila-nacrea 🇬🇧 283 132 3ms 4 Sep 2024 682nd bidger 262 369 411ms 20 Sep 2024 683rd KatieLG 🇬🇧 262 459 1,375ms 15 Sep 2024 684th KatieLG 🇬🇧 260 460 191ms 15 Sep 2024 685th snoozingnewt 🇨🇦 241 444 1,202ms 6 Oct 2025 686th KatieLG 🇬🇧 200 401 125ms 15 Sep 2024 687th KatieLG 🇬🇧 191 398 7ms 15 Sep 2024 688th KatieLG 🇬🇧 171 768 259ms 15 Sep 2024 689th KatieLG 🇬🇧 113 466 3ms 15 Sep 2024 690th Msleizak 🇫🇷 110 424 283ms 7 Feb 2025 691st KatieLG 🇬🇧 103 937 406ms 15 Sep 2024 692nd KatieLG 🇬🇧 86 1,032 399ms 15 Sep 2024 693rd dokutan 64 1,663 92ms 23 Apr 2025 694th dokutan 54 1,663 2ms 23 Apr 2025 695th darrenks 0 10 101ms 19 Apr 2025 695th lyphyser 0 10 92ms 25 May 2025 697th 2bular 0 11 88ms 23 Mar 2025 697th Natanaelel 🇸🇪 0 11 86ms 25 Mar 2025 697th plcc0 0 11 106ms 5 May 2025 700th kg583 🇺🇸 0 14 214ms 12 Apr 2025 701st lyxal 🇦🇺 0 19 673ms 17 May 2025 702nd plcc0 0 20 677ms 20 Mar 2025 703rd namelessiw 0 21 158ms 5 Nov 2025 704th GolfingSuccess 🇬🇷 0 28 130ms 13 Aug 2025 705th AlephSquirrel 0 49 3ms 1 Jul 2025 706th KatieLG 🇬🇧 0 50 4ms 9 Feb 2025 706th Shanethegamer 🇺🇸 0 50 4ms 29 May 2025 708th Nxllpointer 0 55 3ms 10 Nov 2025 709th ovs-code 🇩🇪 0 71 14ms 8 Jun 2025 710th GolfingSuccess 🇬🇷 0 75 2ms 5 Aug 2025 711th sean-niemann 🇺🇸 0 90 91ms 27 Apr 2025 712th HumanoidCPU 0 111 84ms 22 Nov 2025 713th edsrzf 🇳🇿 0 135 184ms 26 Jun 2025 714th dokutan 0 212 68ms 28 Jun 2025 First Prev 641–714 of 714