The eventsView object gives you details about how far into the future you can
easily get a complete picture of a calendar. Subscribing to the event view
webhooks lets you keep track of a calendar's single-occurrence, EXCEPTION, and
INSTANCE events at least one year into the future.
End date of the event view in YYYY-MM-DDThh:mm:ss.sssZ format.
Number of days from now until the event view ends.