Age Potentials by Last Time Activity (ie last call)

Age Potentials by Last Time Activity (ie last call)

I am wanting to age our potentials by last time called/activity. This would require a schedule to run every night to set each potential to last call grouping (ie: Under 14 days, 15 to 30 days, 30 to 45 days etc). I am having troubles trying to figure out how to do this? Any ideas