Note: in Excel’s date system,dates are serial numbers.
January 1, 1900, is number 1 and later dates are larger numbers.
To display date values in a human-readable date format, apply anumber formatof your choice.
DAY Function
The Excel DAY function returns the day of the month as a number between 1 and 31 based on a given date. You can use the DAY function to extract a day number from a date into a cell. You can also use the DAY function to extract and feed a day value into another function, like the DATE function.
