Here is how this works.
You go to this wikia page
http://onepiece.wikia.com/wiki/User:...,_and_Birthday and find the character that has the same birthday as you and you post his or her picture here.
Or:
January
1 - Portgas D Ace & Daz Bones & Islewan
2 - Peeply Lulu
3 - Iceburg & Aisa
4 - Crocus & Peterman
5 - Strawberry
6 - Tilestone & Oimo
7 - Mozu
8 - Emporio Ivankov
9 - Pickles
10 - Eustass Kidd & Otohime
11 - Itomimizu
13 - Ikaros Muchi
14 - Sweet Pea
15 - A.O
17 - Capone Bege
18 - Splash & Splatter
19 - Spandine
26 - Nero
27 - Lola
31 - Aladdin
February
1 - Brogy & Doma
2 - Nefetari Vivi & Killer
3 - Fuza & Brownbeard & Bizarre
4 - Nyon & Fukaboshi & Haruta
5 - Vista & Blamenco
6 - Nico Robin & Nico Olvia & Blondie
8 - Gonbe & Onigumo
9 - Bartholomew Kuma & Genbou & Wadatsumi
10 - Mikazuki
12 - Little Oars Jr.
15 - Charlotte Linlin & Daisy
16 - Bluejam
20 - Kumadori
22 - Hamburg & Jerry
23 - Makino
24 - Enishida
28 - Woop Slap
March
1 - Minorhinoceros
2 - Sanji & San Juan Wolf
3 - Galdino & Hina
4 - Mashira & Minotaurus
5 - Sadi-chan & Minokoala
6 - Jaguar D Saul & Salome
7 - Minozebra
8 - Zambai
9 - Franky & Shanks & Dracule Mihawk
10 - Sentoumaru & Satori & Nola
11 - Palms
12 - Stelly
13 - Lafitte
14 - Smoker & Alvida
16 - Tom
19 - Scratchmen Apoo & Atmos
20 - Sabo & Shiki
21 - Lieutenant Spacey
24 - Thatch
25 - Ohm
26 - Tsuru
29 - Catarina Devon & Saint Shalulia
30 - Manboshi
31 - Judge Baskerville (Bas, Kerville and Princess)
April
1 - Usopp & Kashi
2 - Jinbei & Zeff
3 - Brook & Porchemi & Monda
4 - Shirahoshi & Foxy
5 - Yamakaji & Minister of the Right
6 - Edward Newgate & Speed Jiru & Jean Bart
8 - Doctor Clover & Megalo
9 - Yorki & Margaret & Mohmoo & Caesar Clown
10 - Forest Boss
13 - Morgan
14 - Hody Jones
15 - Fossa
16 - Stronger
18 - Hyouzou
20 - Blueno
22 - Kuro
23 - Kalifa
28 - Funkfreed
29 - Ms Goldenweek
May
1 - Kaido & Capote
2 - Monkey D Garp & Coribou
3 - Arlong
4 - Ishilly
5 - Monkey D Luffy & Demaro Black
6 - Enel
8 - Shakky
9 - Sengoku & Kong
10 - Heracles-n
13 - Silvers Rayleigh & Coby
18 - Gorilla
19 - Andre
20 - Conis
22 - Decalvan Brothers
23 - Chew
25 - Big Pan
31 - Lacueva
June
1 - St Charloss & Moda
2 - Rob Lucci & Chimney & Ronse
3 - Mousse
4 - Epoida
5 - Jyabura
6 - Momonga & Karma
7 - Perona
8 - Saldeath & Lacroix
9 - Rockstar & Surume
10 - Portgas D Rouge & Dalton
11 - Shiryuu
12 - Disco
20 - Amadob
22 - Gyro
24 - Ryuuboshi
28 - St Roswald
29 - Fukurou
30 - Elmy
July
2 - Minister of the Left
3 - Nami & Neptune
4 - Caribou
6 - Lucky Roo & Namur
7 - Laki
8 - Paulie & Daruma
10 - Kamakiri & Ramba
16 - Helmeppo & Seto
17 - Hammond
23 - Richie
29 - Kadar
August
1 - Urouge & Aphelandra
2 - Yasopp
3 - Inazuma & Marshall D Teach
4 - Amazon & Dirt Boss
5 - Basco Shot & Gaimon & Octopako
7 - Kaku & Sodom & Gomorrah
8 - Buggy
9 - Wapol
10 - Hattori
15 - Bentham
16 - Sakazuki
18 - Wiper
19 - Motobaro
22 - Vander Decken IX
25 - Corgi
27 - Monet
28 - Hannyabal
30 - Curly Dadan
September
1 - Jewelry Bonney & Kiwi
2 - Boa Hancock
3 - Boa Sandersonia & McGuy & Brandnew
4 - Wanze & Kumashi
5 - Sir Crocodile & Boa Marigold
6 - Gecko Moria & Squardo & Macro
8 - Cabaji & Rakuyo
9 - Basil Hawkins & Madame Shyarly
10 - T-bone & Very Good
11 - Montblanc Cricket
12 - Curiel
13 - Hoe
15 - Spoil
16 - Laboon & Rindo
18 - Devil Dias
19 - Don Krieg
20 - Shura
21 - Kuzan & Pappug
24 - Su
30 - Avalo Pizarro
October
1 - Comil
2 - Dorry & Tonjit
3 - Yama
4 - Calgara & Oars
5 - Marco & Van Auger & Monkey D Dragon & Kokoro
6 - Tashigi & Trafalgar Law
8 - Doberman & Pierre
9 - Magellan & Dosun & Noland
10 - Den & X Drake (Databook)
13 - Izo
14 - Haredas
15 - Taroimo
18 - Doc Q
20 - Tyrannosaurus
23 - Donquixote Doflamingo
24 - X Drake (SBS)
25 - Kuroobi & Koala
30 - Domino & Magra
31 - Whitey Bay & Shelly
November
1 - Dalmatian
3 - Keimi
4 - Kashigami
5 - Fisher Tiger
6 - Ryuma
7 - Holy
9 - Albion & St Jalmack
11 - Roronoa Zoro & Jozu & Zeo
13 - Kingdew
16 - Porche
19 - Benn Beckman
20 - Bepo
23 - Borsalino &Ankoro
24 - Ran
26 - Goro
December
5 - Indigo
19 - Dogra & Hogback
22 - Gan Fall
24 - Tony Tony Chopper
25 - Jesus Burgess
30 - Absalom
31 - Gol D Roger