I am using the "VisibleDates" collection of SfSchedule to see what is the range of days that are shown in a Month View. I think that the dates are not exactly precise though.
As you can see in the attached screenshots, I am showing the month of May 2019, and the first visible date is April 28, and the last visible one is June 8.
Nevertheless the first "VisibleDate" in the collection is 04-27 22:00 (correct if we consider it's in UTC), but the last visible date is 06-07 22:00 (still UTC). This is actually not correct, as it excludes June 8. The correct last visible date should be, in my opinion, 06-08 22:00.