I am working on creating a solution for our membership department and could use some suggestions on programming it. I think the way to go would be to use Workflow Rules and a Time based email. Process Builder might be another approach. I would be using the:

1st email sent would be Membership End Date field minus 30 days
2nd email sent would be Membership End Date field minus 14 days
3rd email sent would be Membership End Date + 1 date

Any help would be appreciated.

The scenario would be this:
Annual Members: We recently ended our subscription with Click & Pledge and are now using Classy, however, we still have approximately 110  members who paid for an annual membership in Click & Pledge over the last year. That means that we still have people whose Click & Pledge annual memberships will be expiring until early May 2019. Normally many of these memberships would automatically renew, however, because their card numbers were stored in Click & Pledge, the membership will be lost. Our hope is to retain these members by sending them re-enrollment emails.
Annual Cash/Check Members: We also have about 65 members paying by check or cash, that we would like to send an automatic renewal reminder to when their annual membership expires. 

Desired Outcomes
For each expiring member, we would like to send them three different emails:
Email 1: Sent 1 month prior to expiration date
Email 2: Sent 2 weeks prior to expiration date
Email 3: Sent day after expiration date