As per the general practice of the organisation two half day will be counted as one day leave within a specified period. In your case where you have take half day leave on Friday & Monday...This should be counted as one day leave only.
If you would have taken Full day on Friday & Monday then it could be 4 days leave i.e. Friday, Saturday, Sunday & Monday.
PS : On leaves, every company has their own policy & employees has to comply with the same.
6th February 2014 From India, New Delhi