Hi Kendrix,
There is no built-in service in IS which accepts 2 dates as input and gives you the out the noOfDaysDiff. So write a Java service.
Just do a google search and you will find lots of Java code snippet which does that.
First try yourself, if you find difficulty writing such code, we can send you the code.
This is very common utility we all webMethods veteran frequently need and so we have it.
Regards,
Bhawesh.
#webMethods#Flow-and-Java-services#Integration-Server-and-ESB