One of the benefits of Retreva is the schedule is built for you and you do not have to worry about it. Each contact is tracked independently and we consider things like time of day, day of the week, holidays, and major national events like the Superbowl.
The idea is just to keep adding contacts and contacts will be on various different schedules creating daily activities for you.
If you have something that is time-sensitive, you can send a one-time message. This feature can be found on the contact page but otherwise, we recommend you just let the schedule go.
If you need to change something for an individual contact, search for the contact in the Contact view and apply the correct reply action from the Action drop-down.