I am developing a system that need to monitor machines' licence, so i have a field 'movedate' and 'outdate'
every machines can only been kept for 2 years for most.
and if the machine didn't go out for almost 2 years, an alert will come out to remind the tenant.
I want the alert will come out about 2 weeks before the expire date.
But Im not sure how to do it..can someone guide me?