When you give DATE a year and month value, and a zero for day, you get the last day of the previous month.
Note that you use the YEAR function to pull out the year portion from the actual date. For this one, you have to find out how many days have elapsed since the beginning of the year.
Developed in the 16th century by Joseph Scaliger, the numbers were based on a 7,980-year cycle that began on January 1, 4713 BC and ends January 22, 3268.
Contrast with "Gregorian date," which is the common calendar notation of month, day and year.
You can use the YEAR function to extract a year number from a date into a cell.
You can also use the YEAR function to extract and feed a year value into another...