What kind of workflow action is needed to complete the requirement in Salesforce?

Universal Containers wants to proactively alert each of its sales team users 30 days before their account renewal is due. To do this, a ‘required’ custom account date field named ‘Renewals’ has been created to hold the accounts’ Renewal date. The default is one year from ‘Create Date’. A validation rule ensures the date value entered is at least 30 days into the future. An Email alert and Email template has been created and is set to be delivered to the Account Owner recipient.

What kind of workflow action is needed to complete this requirement?