Do you have any leave policy? What does it say about the sandwich leave policy?
If at all you don't have any policy as such there are 2 options.
1) As per the leave rules if any employee avails leave between Friday to Monday then the same shall be treated as 4 days leave.
2) There are many companies in favouring the employees as if any employee avails leave between Friday to Monday & if you are working 5 days a week they will consider 2 days leave & if you are working 6 days a week then its 3days as leave.
Now you can take the appropriate calculation by approaching top management. Later its always advisable to make clear leave policy to avoid the confusion
If any more information you can reach me
22nd June 2016 From India, Bangalore