I am in need of some sort of calendar calulator. From within a shell script i set a variable to a date by using the date command. I then need to be able to set another variable to a date that is 2 weeks ( 14 days) later. I will then compare this new date to the current date to determine if this item is overdue. I would then issue some kind of email message to the particular party. Is there such a tool available, or is it possible all within shell scripts?