I am not a huge technical person but I looked at the formulas with http://www.pacificdb.com.au/MVP/Code/Dates.htm and here is what I came up with but isn't working
=DateDiff("d",[Receipt Date],Date())-DateDiff("d",[Receipt Date],Date(),1) * 2 If(Date(), 1) = 7, If([Receipt Date], 1) = 7, 0...