Problem with dates, it is urgent

Hi,

Presently I am using function module

DAY_ATTRIBUTES_GET

Where I am passing two dates,

the first date pertains approval date of the document,

the next date is 3 days plus of approval date of the document

But I need to check whether the days between two dates does not fall under holidays or free days ,free days means Saturday and Sunday.

From this function module we can get the list of the holiday & free days,

if the days between two dates fall under holiday or free days we need not calculate holidays & free days instead we need to give 3 working days from the approval date.

Can some one help me with the logic.

Thanks in Advance,

Irfan Hussain