sending out a reminder email using Send Emails Later

In my form i have to date options found in the first question, Date wishing to attend that a user can select and based on which one they select i want a email to be sent later on a specific date depenind on which date they selected, how do i do this ?

Please note that you can set your form's auto-responder email to trigger on a certain date. Check the screenshot below:

You can also use the following app to send email newsletter to all your users as well:  http://email.jotform.io/