Calculate last working / business day of week

[Rkornack]

I am working with a dataset of stock market trade data going back to 1998. There are only line items on trading days, so no weekends or holidays. I need to determine the last working/business day of week, so that may be a friday or thursday depending on holidays. 

I've created a dayofweek column, DateTimeFormat([Date], '%u'), which ranks the day of the week 1-4

I also have a week number column DateTimeFormat([Date], '%W') which gives 1-52

and a year column DateTimeFormat([Date], '%Y') which gives year 2004

I'm trying to build these in to a chart that I can use a lookup previous value in some way, but I'm stuck. Any help would be appreciated

[CoG]

It looks like you already opened a thread for this challenge. I encourage you to stick to one thread for each issue so that you can receive the best help. I already posted a suggestion on your first one. It also helps others looking for solutions, not get confused :)