InfoPath Dev

I have created an InfoPath form in 2003.  It has a start date and end date to figure total days.  The following link is where I got the rules. 

http://enterprise-solutions.swits.net/infopath2007/calculate-date-difference-infopath-rules-formulas.htm

How and where do I modify the calculation to subtract 1 day for total quantity?

Welcome to the forum

http://www.infopathdev.com/forums/p/5646/21172.aspx#21172

That should give you a sample for calculating 90 days, just change for 1.