Excel 2007 : Processing Time that excludes holiday, weekends, and non-business hours

this is my first post so if you need more info just let me know.

I am trying to write a formula that will calculate the time between two dates/times. The clock should stop on all weekends and federal holiday. It should also stop at 5 PM and resume at 8 AM the next business day. If the second date is during a non-working day or hour, it should calculate as 5PM the previous business day

The following formula gets me part of the way but it seems to have a problem when the start date is on a holiday or weekend.

=IF(AND(INT(A5)=INT(B5),NOT(ISNA(MATCH(INT(A5),D$2:D$113,0)))),0,ABS(IF(INT(A5)=INT(B5),ROUND(24*(B5-A5),2),(24*(F$2-E$2)*(MAX(NETWORKDAYS(A5+1,B5-1,D$2:D$113),0)+INT(24*(((B5-INT(B5))-(A5-INT(A5)))+(F$2-E$2))/(24*($F$2-$E$2))))+MOD(ROUND(((24*(B5-INT(B5)))-24*E$2)+(24*F$2-(24*(A5-INT(A5)))),2),ROUND((24*(F$2-E$2)),2))))))

A=Application date
B=First activity date

D=List of excluded dates
E=Business day start time
F=Business day end time

I have attached a sample spreadsheet with the formula above.

Thanks for the help