The DATE function in Excel allows you to work with dates by providing a serial number based on the year, month, and day values you specify. Here are some examples:
To get a serial number corresponding to May 20, 2015:
=DATE(2015, 5, 20)
This returns the value for 20-May-2015.
To find the first day of the current year and month:
=DATE(YEAR(TODAY()), MONTH(TODAY()), 1)
This formula gives you the first day of the current month.
To subtract 5 days from May 20, 2015:
=DATE(2015, 5, 20) - 5
The result will be 15-May-2015.
Remember, the DATE function is essential for accurate date calculations in Excel.