Workflow Rule: Setting a recurring rule whenever a field is updated

Workflow Rule: Setting a recurring rule whenever a field is updated

Hi,

I am setting up a workflow rule with a scheduled action to deliver an email to a customer 19 days after an order has been made.

The trigger is set when the "Total Commission" field updates. i.e. this indicates the customer has bought something.



I want this rule to trigger every time someone makes a purchase. i.e. every time the "Total Commission" field updates. But scheduled actions isn't available if I tick the " Repeat this workflow whenever a account is edited" box:



I assume this needs to be ticked otherwise the rule will only trigger the first time the "Total Commission" field updates? Or am I not reading the help docs correctly? If I tick this box then I am stuck with only instant delivery of the email.

If it has to be ticked is there another way to achieve what I want?

Thanks Very much!