copy of headings and some sample data

Pat,
I have attached a copy of headings and some sample data both in txt and a zipped excel
Thanks for your help....

Hello I hope someone can help with this. I need to subtract dates in current record from previous record for the current store.
The key fields in the form are customer, store number and date picked up.
I have used a query to put all records in order of consumer, store number and date picked up and I am using a form to view it. I can use =max([date picked up])-[date picked up] to do the subtraction but I need to only be looking at like...