There are instances when you want a call handled differently if it is logged during the week or on a weekend. It would be nice to be able to configure an IPK Workflow rule that says "If Call Logged Date is a Saturday or Sunday" then do this... Or if the call logged date is a Sunday and it is between the hours of 2PM and 10PM then do this.
I think the ability to configure relative dates on all date fields will be a useful addition.