Create Notification For Custom Date Fields - Due Date Notification

Hi All,

 
 We have HP SM 9.30 in our environment.. We have got a requirement - Email notification to be shoot out "if the due date is going to get expired in nexe two days "

 We created two date fields in "sd.update.interaction" form as 'Start.Date' and 'End.Date'. and our helpdesk team will choose the start.date & end.date while updating / saving the tickets..  SM should periodically check the values in 'End.date' and send a remaineder mail notification to a concern person if the 'End.Date' is going to expire in nexe two days..

 I am new to this tool and anyone can help me on this