title: Sharepoint Designer - is there a way to calculate a date difference in a workflow?
body: <p>Maybe I'm just crazy... So, with SPD I can add any time unit to a date and put that into a variable, but I can't seem to find anything that will let me calculate the difference between two dates.  "Do Calculation" only lets me pick from numeric values.  Am I missing something here? Seems like something which should be obvious.</p>