Sending delayed emails with node-mailer on Heroku

I have a MEAN stack web app being hosted on Heroku. I'm using node-mailer (http://ift.tt/Hgzl9A) to send emails when people create a form, sign up for a form, and a few other things.

Ideally, I would like to send a reminder email one week prior to the date specified on the form.

I have no idea how to accomplish this with node-mailer, and have been scouring google looking for a solution, but come up short.

Is there a good way to send delayed emails with node-mailer? I don't want to switch mailing services if I can avoid it.

Thanks in advance.