If Today is August 10th, and Jin is 28 in korean age right now and his birthday is August 11th and Yoongi is 28 Korean age and his Birthday is August 13th, on august 11th, Jin will be 29 Korean age and 27 international, while Yoongis birthday is a day later, but same year
This happens because in Korea you are automatically 1 year older than you are in international age. For example: if you are 15 in international age you will be automatically 16 in Korean. if your birthday is August 8th you will be 17 because your birthday has already passed but if your birthday has not passed yet than you will be 16 in Korean age not 17. Therefore, still making you 15 in international age.
