How to determine calendar visible days' start/end date

Hello,

I have a weekly calendar that shows some scheduled events – say 20 total for example. This week for example, the start date is 10/11 to 10/17.

I’d like to show a user a count of the number of appointments. To do this, I believe I need to query the DB based on the calendar start/end dates. This would allow the user to select day/month for a calendar view and assuming it’s possible to pass the calendar start/end date the query would return the correct amount of appointments.

Looking at the data bindings available in front end for the calendar, I don’t see anything like a variable I can use elsewhere:

Does anyone know how to determine the visible calendar’s first/last days’ dates so they can be passed as GET params for a query?