How do I count down the days...?

[HeatherDawn]

Can someone help me with a function that will automatically count down the days until a tenants rent it due?

[duane]

if you put the due date in cell a1, use =a1-today()

[HeatherDawn]

Ok, sorry changed my mind....here's what I need to do:

I don't really know the due date...the tenants rent for a certain amount of weeks at a time, and I wanted to count down from say...56 days. So, if a1 was 56, how would I count down from there? Is that possible? Also is it possible to automatically email me when it says 2 days are left? Thanks