Visually show the status of an event ("free", "tentative", "busy") in the calendar overview

I want to see the status of an event (“free”, “tentative”, “busy”) in the calendar overview without having to use the mouse over tooltip box. This would be most useful if I have to quickly assess open slots for additional events. 

Other programs (Outlook, Thunderbird Lightning) show visual indicators for the statuses as well: Link

After many eM Client improvements, this is the only reason why we don’t use eM Client in our company. Thanks