According to SBS Volume 15, Oda said that Sanji's birthday is March 2nd.
He often bases birthdays on the character's name. The kanji for each number can be 'read' in different ways, ie you can read them in their original Chinese way or in a way that uses Japanese and describes the meaning. That gives each word a bit of versatility.
So in this case 'San' means 3, representing March, and 'Ji' is the Cantonese way of reading the Kanji for 'ni', meaning '2', representing the second day of the month.
Luffy's birthday is May fifth.
sanji [from onepiece] He is born March 2nd, a Pisces. His birthday comes from "San", which can mean the third or three, and "Ji" which means the second. The second day of the third month. he is 19. also:"Sanji" is a way of saying "three'o'clock" in Japanese.
Soru
Sanji joined the crew in episode 30
Sanji is rendered helpless by Kalifa due to her Awa Awa no Mi powers and his inability to hit a woman. After Nami challenges her in his place though, Sanji goes on to defeat Jyabura.
They never kissed in any episodes, not even an almost one.
March 2
sanji [from onepiece] He is born March 2nd, a Pisces. His birthday comes from "San", which can mean the third or three, and "Ji" which means the second. The second day of the third month. he is 19. also:"Sanji" is a way of saying "three'o'clock" in Japanese.
Soru
In the One Piece series, Zoro and Sanji have a complicated relationship that mostly involves playful rivalry and disagreements. There are moments where they show respect and teamwork towards each other, but their dynamic is often characterized by banter and competitive spirit rather than overt displays of affection.
Sanji Abe was born in 1895.
Sanji Kojima was born in 1938.
Sanji joined the crew in episode 30
Sanji Mmasenono Monageng was born in 1950.
Sanji Hase's birth name is Hirao Hase.
sanji uses tokui taijutsu (leg taijutsu)
Sanji Hase died on March 8, 2002, in Toshima-ku, Tokyo, Japan of lung cancer.
Sanji Hase was born on January 2, 1936, in Tokyo, Japan.