Macro To Add Business Hours / Days To Date

Where i want add Business Hours/Days to get the Target Date.

Working hours: 8:00 AM to 19:00 PM

Urgency Type:

ND (Maximum 1 Day 11 hours)
3D (Maximum 3 Day 11 hours)
4D (Maximum 4 Day 11 hours)
5D (Maximum 5 Day 11 hours)
Threshhold - 16:30 PM
Weekends to be Excluded.

Holidays to be Excluded based on Country. Say I have 2 countries India and America, where America has holiday on 12/24/2012 but India does not have holiday on that Day. Hence while calculating Tgt date, India should be calculated normally, for America holiday date need to excluded(There will be a Holiday table based on the countries, not limited to 2 countries).

ex: 1) A ticket opened at 12/26/2012 8:56 AM; Target date will be 12/26/2012 19:00, in this case its 1 day 10:04 hours added to the Opened Time.

2) A ticket opened at 12/26/2012 16:56 PM; Target date will be 12/29/2012 19:00, in this case ticket opened after threshold time of 16:30, Technically ticket should start from next day i.e 12/28/2012 8:00 AM and 1 day 11 hours added to this date.

3) A ticket opened at 12/26/2012 7:56 AM(Before the begin of Working hours); Target date will be 12/26/2012 19:00, in this case its 1 day 11:00 hours added to the Opened Time.

4) A ticket opened at 12/21/2012 17:56 PM(After Threshold time); Target date will be 12/24/2012 19:00, in this case its 1 day 11:00 hours added to the Opened Time. If the above ticket belonged to America, then holiday dates(both 24 & 25) need to be skipped and Tgt date will be 12/27/2012 19:00.

Here is the Sample Data

Country
Ticket
Start Date/ Time
Tgt Date/Time
Expected Tgt Date/ Time

America
ID000123
12/21/2012 18:20

[code]....

I need results to be appear in the "Tgt Date/Time" column. I have also provided results in "Expected Tgt Date/ Time".