when date of birth is A1 and i use the formula
=date(year(A1)+19,month(12),day(31)), to get the last day of the year before
the 20th birthday, 31/1/1919 appears instead of 31/12/1919. why is this? if
i take the +19 away, the same thing happens. The only time it works is if i
specify the year instead of using another cell.