There will be a Schedule tile on Segmented Campaign Home.
Click Select Schedule to set the Global Schedule.
The standard scheduling options will be provided.
Edit
Once the Global Schedule is set, use Edit Schedule on the Schedule tile to get back to the scheduling options.
Send Immediately
If admins select Send Immediately, this will be assigned to all versions.
It cannot be modified at a per version level.
Send on Specific Future Date(s)
If admins select Send on Specific Future Date(s), they will be setting the global schedule. This will be reflected on all versions.
The schedule can be changed on a per version basis by clicking on the date/time link for a version.
NOTE: Making a change to the date/time for the Global Schedule will not force versions to the updated date/time. If you change the schedule type, all versions will follow the updated schedule.
Example: The Global Schedule is set to January 15, 2020. One version is set to January 17, 2020. If I change the Global Schedule to January 18, 2020, the version set to January 17 will continue to have January 17 as the send date. If I update the Global Schedule and change the schedule type to Send Immediately, all versions will move to Send Immediately.
Schedule Recurring Sends
If admins select Schedule Recurring Sends, this will be assigned to all versions.
It cannot be modified at a per version level.