iCal syning current reservations when none present

[HotelManager0]

Hello,
I've programmed our website to generate an ICS calendar file that blocks out reservations we have received through our website using Air BnBs Import feature. This works fine but it fails to recognize a properly formatted file when there are no reservations to sync since the iCalendar file is without any VEVENT parameters.

In simple terms we can not add a link to our remote calendar IF that calendar is without any dates (events) present.

Does anyone know what we should present when no dates are in our calendar as we can't assign the url unless there is an event???