Excel DATEVALUE is a Date and time function, and its purpose is to converts a date in the form of text to a serial number. Learn how to use it.

Formulas are powerful tools for performing calculations and analyzing data in Excel. In this beginner’s guide, you’ll learn how to use formulas and explore some popular built-in functions.

The Excel WORKDAY function's purpose is to return the serial number of the date before and after a specified number of workdays. Learn how to use it.

Bookkeepers, project managers, HR departments and more use the Excel Date & Time functions WEEKNUM, ISOWEEKNUM, WORKDAY, WORKDAY.INTL to calculate time. Here's how.

Unfortunately, if you're using Excel 2019 or earlier, you won't be able to create your own functions using the methods described in this guide.