In countries where the lunisolar calendar is still used or when counting the age of the deceased who lived during the period when the lunisolar calendar (the old lunisolar calendar) was used, age is counted with the New Year's Day as the base date of the calendar used in the relevant country back in these days.
現在も太陰太陽暦を用いている国や、太陰太陽暦（旧暦）を用いていた時代の物故者については、その国の当時の暦法の元日を基準として加算される。