Use of expression for "One day before the due date" and "One day after the due date" in Alerts

Summary:

Which Alert Expression can use for "One day before the due date" and "One day after the due date" in Alerts

Content (required):

Hi All,

We have a requirement where the learner should receive the Alert one day before the due date and one day after the due date.

So, which is the Alert Expression i need to use so that it will work correctly,

As of now i am using the below expressions,

Alert for one day before the due date(-1 day)

${assignmentDueDate} BETWEEN sysdate+1 and sysdate+2

or

${assignmentDueDate} = sysdate+1

Alert for one day after the due date(+1 day)