I've got a large spreadsheet/CSV.

It contains several columns, first one is date, containing a separate row for each day of the year from 2009 to present. The other columns are things like downloads, earnings etc.

I'm wanting to find a way of summarising this data so that I can see by month total downloads and earnings.

Not entirely sure where to begin, thought vlookup might be the badger, but I had 2 hours sleep before getting up at 4AM today so my brain is fried! It seems more hassle than it's worth, when I could just copy and paste monthly summaries. Just thought I should try and do things "the proper" way.