Returns the sequential serial number that represents a particular date.
The DATE function is most useful in formulas where year, month, and day are formulas, not constants.
A number that represents the year. The year argument can be one to four digits.
A number that represents the month of the year.
A number that represents the day of the month.
Excel stores dates as sequential serial numbers so they can be used in calculations. By default, January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900.
If the cell format was General before the function was entered, the result changes the cell formatting to Date.To view the result as a serial number, select the cell, and then on the View menu, click Formatting Palette. Under Number, on the Format pop-up menu, click Number.
To make the following example easier to understand, you can copy the data to a blank sheet and then enter the function underneath the data. Do not select the row or column headings (1, 2, 3... A, B, C...) when you copy the sample data to a blank sheet.