If you need to add more time to your study calendar after your study has gone live (in the case of needing to reschedule someone or extend the research timeframe), you'll do this in the Availability Tab of your study.
We use 5 colors on the calendar:
-Blue: available for a participant to select
-Green: occupied by a participant
-Grey: completed interview
We highly recommend avoiding back-to-back sessions, so you have a little 'buffer' in the case of sessions running long, etc.