The DATEVALUE function takes a date value in any valid format and returns the same date as a serial number. All dates and times are stored as serial in Google Sheets so they will work in formulas (you can add March plus June).
The DATEVALUE function can be used to prepare dates to be sorted, filtered, or used in formulas.
The input for this function needs to be either surrounded by quotes or a reference to another cell with a date in it.
The DATEVALUE function returns a serial number from any valid date.
date_text- The date, written in a text format, that is to be converted
Example 1 - Plain and Simple
|=DATEVALUE("March 1,2017")||March 1, 2017|
This example has a date-value that Sheets recognizes so it is able to return a serial number. In this case, the formatting is set to date, so the serial number is shown as March 1, 2017. If the formatting were set to number, the result of the function would be 42,795.00.
Example 2 - Unrecognized text date
A full date typed as 1st instead of 1. Returns a #VALUE! error. The #VALUE! error occurs whenever Sheets cannot figure out the text date.
Example 3 - Just a day and month
|=DATEVALUE("March 1")||March 1, 2017|
Just a day and a month typed in. The spreadsheet assumes the date should be the current year which was 2017 when this was written. The year value will always be current when view in the live spreadsheet.
Live examples in Sheets
Go to this spreadsheet for the examples of the DATEVALUE function shown above that you can study and use anywhere you would like.