How can I summarize cells based on date in other cell?

Question

I have one Excel sheet with columns "project name", "project date", and "effort estimation".

On a second sheet I want to summarize those projects according to the months of the year.

So I have created a list of month names. Now I want the sum of the efforts for each month based on the information from the first sheet.

How can I accomplish this?

Answer 1

With the three columns you already have, you can create a pivot table. With the pivot table you can then create hierarchical relationships and to totals by month, etc.

You should not have to create anything other than the pivot table on the other sheet.

See this tutorial on Pivot Tables. I have made a quick demo which I think demonstrates what you are trying to do:

Here is an example of a Pivot Table.

Also, if you have different start dates in a given month, aggregation is possible: