Function for Calculating Dates using DatePicker

[Alan]

Can you please explain how I can use a function to return the number of days
between StartDate and EndDate when I try I keep getting a Nan Error and will
not return an number i.e. 14

 

[S.Y.M. Wong-A-Ton]

Try this article:
http://www.bizsupportonline.net/infopath2007/calculate-date-difference-infopath-rules-formulas.htm

 

[Alec Pojidaev]

Compact rules only solution
http://alecpojidaev.wordpress.com/2008/12/30/infopath-codeless-programming-walkthrough-2/