System maintenance taking 5h41m?

Just received notification that my internet service is down for "system maintenance" that will take 5 hours and 41 minutes. This is absurd. How can system maintenance take that long?  Can it not be broken into several shorter interval?  I have several smart home systems that rely on internet connectivity.  At least customer should be notified if such long "system maintenance" is scheduled.

Another reason that makes Xfinity/Comcast NOT my choice company but has to use because there is little to no alternative in my rural area.