Find Duplicates within a specific timeframe.

Is there a way to differentiate the number of unique and duplicate entries (considering multiple criterias) using a formula.

I am finding it hard to describe the request hence i have attached a spreadsheet for reference.

The first tab contains the data where I want the result in 'column J'
The second tab contains the metrics of how to calculate the result.

I am sure this will be difficult to understand at first hence feel free to ask as many questions you would like to [only related to the subject ]

For the record, I use Excel 2007 & 2010.

Appreciate your time.

Thanks in advance.