I would love to be able to set the visibility of a calendar dependent on my current view.
In my case I have my normal calendars and also my work calendar synced into my Thunderbird. While the work calendar is very useful for the week view, so I can plan things like doctors appointments when I don't have meetings scheduled, when in month view my calendar suddenly becomes very cluttered. In month view I don't need to see my work stuff, as I know which days I'm working, and so I would love to disable the visibility when in this view.