Scheduling the timing of emails that are sent in future


I see on the email threads that there is a schedule delivery timing option and I can set a number for days or weeks. How does that work? Is that the amount of time after the first email or the time between each email?
The schedule delivery timing setting is to set the amount of time between emails. If you set the setting as 3 days on email #2, then email #2 will go out 3 days after email #1. Think of this as the amount of delay or pause between emails.