Excel DATE Function With Formula Examples To Calculate Dates

Excel DATE function

The Excel DATE function returns the serial number that represents a certain date. It has the following arguments:

DATE(year, month, day)

Where:

Year - represents the year of the date.

Month - an integer representing the month of the year, from 1 (January) to 12 (December).

Day - an integer corresponding to the day of the month, from 1 to 31.

The DATE function is available in all versions of Excel 365 - Excel 2007.

DATE function - tips and notes

The DATE syntax looks crystal clear and straightforward on the surface. In practice, there may be some unobvious pitfalls that the below tips will help you avoid.

Year

Excel interprets the year argument according to the date system set up on your computer. By default, Microsoft Excel for Windows uses the 1900 system where January 1, 1900 is represented by the serial number 1. For more details, please see Excel date format.

• If the year argument is between 1900 and 9999 inclusive, Excel uses exactly the value you supplied to create a date. For example, DATE(2015, 12, 31) returns December 31, 2015.
• If the year argument is between 0 and 1899 inclusive, Excel adds the specified number to 1900. For example, DATE(100, 12, 31) returns December 31, 2000 (1900 + 100).
• If the year argument is less than 0 or greater than 9999, a DATE formula will return the #NUM! error.

Tip. To avoid confusion, always supply four-digit years. For example, if you input "01" or "1" in the year argument, your DATE formula will return the year of 1901.

Month

• If the month argument is greater than 12, Excel adds that number to the first month in the specified year. For example, DATE(2015, 15, 5) returns the serial number representing March 1, 2016 (January 5, 2015 plus 15 months).
• If the month argument is less than 1 (zero or negative value), Excel subtracts the magnitude of that number of months, plus 1, from the first month in the specified year. For example, DATE(2015, -5, 1) returns the serial number representing July 1, 2014 (January 1, 2015 minus 6 months).

Day

As well as month, the day argument can be supplied as a positive and negative number, and Excel calculates its value based on the same principles as described above.

Tip. At first sight, supplying negative values in the month or day argument of the Excel DATE function may seem absurd, but in practice it may turn out quite useful, for example in the complex formula that converts a week number to a date.