After a Visit has been scheduled, you can still make changes to the Visit details.
To begin, navigate to a scheduling page (a Client, Employee, or Facility Schedule or the All-Client or All-Employee Schedule) and click on the Visit you would like to edit. Click More Details.
In the resulting dialogue, select the Edit tab.
Make the necessary changes and then click Update Visit.
If you only need to change the date or time of the Visit, you can simply drag the Visit tile to the time on the calendar to which you wish to reschedule the Visit.