Merge Calendars

I am a cleaner with limited access to 3 different hosts' calendars.  It is time consuming to toggle between multiple calendars.  Can a "merge calendars" feature be added, only viewable to me?  

Is anyone else interested in this feature, even if you weren't a cleaner?

I understand the problem, but I think there is a better solution. They should implement a "Calendar invite" which can be triggered by events such as departure date. This would allow you to have a single calendar with events from multiple properties. My cleaning service has this with owners who use other PMS software, and she is unhappy we cannot do it.