The following are Google Calendar screenshots.
I'm assuming this is the goal for syncfusion flutter calendar as well.
The calendar treats an appointment date range 3 different ways:
Single day:

Spans 2 days (note it only shows on the first day):

Spans more than 2 days:

At the moment, syncfusion splits the 2-day span into two slots, one for each day, which is not compliant with the above Google Calendar screenshot.
I'd like to propose a feature request to add this by default or with a boolean option showRolloverOnFirstDayOnly in scheduleViewSettings