Here are the official YOI birthdays for all the characters introduced so far…

• Viktor Nikiforov: December 25 (Capricorn)
  
• Yuuri Katsuki: November 29 (Sagittarius)
• Yuri Plisetsky: March 1 (Pisces)
• Georgi Popovich: December 26 (Capricorn)
• Christophe Giacometti: February 14 (lmao) (Aquarius)
• Guang-Hong Ji: January 7 (Capricorn)
• Phichit Chulanont: April 30 (Taurus)
• Kenjiro Minami: August 18 (Leo)
• Leo de la Iglesia: August 2 (Leo de la Iglesia)