In Vietnam, every person celebrates their birthday on the same day of the year, which is Tết Nguyên Đán (pronounced “tet!/tut! hwin dawn” with the exclamation marks denoting that “tết” is a strong sounding term with emphasis), the Vietnamese New Year. Instead of celebrating individual birthdays, the Vietnamese celebrate birthdays simultaneously by collectively adding a year to their age upon this date. Tết Nguyên Đán is predicated upon the lunisolar calendar, which involves both lunar and solar events, and because of this, Tết Nguyên Đán occurs between January and February, marked by the first new moon after January 21st but before February 20th. It should be noted, some Vietnamese have chosen not to observe this tradition, and therefore celebrate their individual birthday upon the date of its anniversary, with this practice becoming much more common during the modern day, however because Tết Nguyên Đán is the most important holiday within Vietnam, the practice is still ascribed to
