When you view your video Library in the Arlo app, the days of the current month display underneath the name of the month. You can drag the row of days left or right to move backward and forward in the Library calendar:
If you drag far enough that more than half of the displayed days are from a different month, the name of the displayed month changes. For example, if you are viewing October videos and you drag the row of days to the right, as soon as the last day in September passes under the name of the month and you stop dragging, the month changes to September:
For more information about how to use the calendar to view your Arlo videos, see How do I use the calendar?.