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.

Does anyone know of a way to use the WEEKNUM function but to have it display the week number relative to a specific date? For example, If my column of dates starts at May 7th, where I would like ...

How to Use AVERAGEIF in Excel Excel's AVERAGEIF function allows you to calculate the mean of a dataset that has been filtered based on a single condition you set.