In One Piece, when is Luffy's birthday (year, month and day)?

Luffy-Monkey D Luffy [モンキールフィィ] [Features] Wearing a straw hat, there is a scar under his left eye. [Specialties] Demon Fruit Capable Person. After eating rubber fruit, the body can stretch at will. [Goal] Become one piece and get the one piece, the last secret treasure of one piece, Grudo Rosa. [Height] 172cm [age] 17 years old [birthday] May 5th [reward] 1 100 million constellation: Taurus height: 172cm Birthplace: windmill village identity: captain's devil fruit ability: rubber fruit is the most precious thing: Sagus gave it to him with red hair. He can understand other people's thoughts and risk his life unconditionally for his companions. He is a reliable captain. Disadvantages: overeating, impulsiveness, simplicity, stubbornness, dullness, ignorance, forgetfulness and stupidity. Unique skills: rubber gun, rubber gun, rubber bullet, rubber postmark, rubber whip, rubber tomahawk, rubber rocket, rubber spear, rubber sickle, rubber clock, rubber hammer, rubber stick, rubber crossbow, rubber net, rubber windmill, rubber shield, rubber balloon and rubber stutterer grew up in an island fishing village. I have a good relationship with Sagues, a red-haired pirate temporarily stationed in the fishing village, so I want to be a pirate. The scar at the moment is to show that you are cruel enough, and you cut it with a knife (really cruel enough, sweating). However, when Luffy was 7 years old, he ate the devil's fruit-rubber fruit (ゴムゴムの実) and was taken away by pirates. Since then, he has never learned to swim. Can you still be a pirate? Luffy's answer is-as long as he doesn't fall into the sea (it sounds reasonable, but ... I was really defeated by this single-celled guy). Once, in order to defend the reputation of pirates, Luffy and a mountain thief pressed each other and almost died. Fortunately, the pirates arrived in time. But Luffy was thrown into the sea, and Sagues was bitten off by a fierce marine animal to save him. (This passage is really touching ~ ~ ~) Sagues with red hair put his straw hat on Luffy's head before he left the fishing village to go out to sea again. "You must give it back to me in the future, when you become an excellent pirate!" Ten years later, Luffy really went to sea. His goal is-One Piece! And that straw hat has become Luffy's most cherished treasure.