In the Overview / Multi Plan View, you can extract a day from your multi-day session to become a separate single session. Just click on the further options icon (the three vertical dots) under the day-session’s name, and select the option ‘Extract’. The extracted session will now be a separate session, accessible from your workspace and from the list of your most recently modified sessions on your Homepage

Please note that in order to extract a day, you need to be either the owner of each session involved, or have workspace admin rights if the affected sessions are in that workspace.

In case you accidentally extracted one of your day-sessions from your multi-day session, you can still merge it back into your multi-day session.