What is a good example to set a task that is due on specific event date?

I am working on a project for our CRM product, which the user required to have an ability to create task that's due certain days before and after a milestone date for a transaction (eg. closing dates for Real estate agent). Some of them would also request for making it repeating.

My question was how could i make the flow to set due time and recurrence a little easier on both mobile and web. Is there any great example for that?

This is my initial flow for it, but thinking it could be better.(calendar is just a place holder