Schedule Task X days (or hours) after workflow started

I'm new to Orchestrator so please forgive my ignorance...

I'm building a workflow that allows our users to create their own snapshots.  We have a policy that snapshots can only be kept for a maximum of 3 days.  My inputs would allow the user to select the number of days (I'm cool with using hours if it's easier) until the snapshot is automatically committed.  How would I accomplish this?  Is there a method to take the current date/time (at the time the workflow is run) and add X days (or hours) to schedule a task that commits the snapshot?

Alternatively, is there a way to present a calendar and only allow them to select up to 3 days from the current date?

Thanks for any contributions