6 month backdated list of work days that updates

Hello All,
I need to make a 6 month backdate list of dates (only work days) starting for the date on which the excel spreadsheet is open.
For example if i open it today (02/07/2012) i want a list going back 6 months only displaying work days.
Is this possible?

i thought there was a work day function but i cant get it to work with an auto date update...

if possible i need it to factor in a list of holiday days that update is that even possible, does excel know when columbus day is for example?
New Year's Day
Martin Luther King Birthday
President's Day
Good Friday
Memorial Day
Independence Day
Labor Day
Thanksgiving Day
Christmas (observed)


can someone help me out

Much appricated.