King Bhumipol Adulyadej was born on December 5, and this day is now celebrated as Father’s Day across Thailand. Thai people may give a dok Buddha ruksa (also known as a canna flower) to their fathers and grandfathers on this day and it is also Father's Day All Thailand is dressed in yellow on this special day, as the King was born on a Monday, the day of the week to which yellow is associated. Thai people often wears a yellow shirt on Mondays, throughout the year, or on every occasion where they want to show their love and respect of the King.