The function DATE is very useful to create your custom dates. This article will explain you how the function works
If you want to calculate the difference between 2 dates in Excel, you have to use a hidding function . It's the function DATEDIF.
This article is a glossary of all the Excel functions to return the first day or the last day of the Month, the Quarter or the Year
With Excel, you can build your dynamic date very easily. Discover how to build a dynamic date in this article.
Formula to calculate the first Monday of the month with Excel