Create matrix table

Dear Community, 

I am quite new to PowerBI, so any help is highly appreciated.

I have a table of records, where each record has an opening date and a closing date (and lots of other columns, but to understand the basic functionality i will just work with those three columns - record #, opening date, closing date).

I want to create a matrix, where the columns represent the Months (April to March), and the rows represent the sum of the records for the corresponding month (see example). OutputInput

I already have a Date Dimensions Table (not sure if i really need it).

Please, i need some starting help !Where to put which data and so on...how to set the relationship (if i need it).

Thank you so much!