I am not waiting for the regular Beta of Catalina to arrive next month. I installed the Developer version into Parallels Desktop for testing. At this stage of the game, some things just do not work. But, I can still test some things like the new Automatic Time of Day on off for Dark Mode.
Automatic Dark Mode
In Mojave you could set the Desktop to Automatic. If you were in Light Mode for your Desktop, the Desktop would darken as the day progressed. However, this feature was omitted if you were using Dark Mode. That is no longer the case in MacOS Catalina.
If you prefer to use Dark Mode and wish to have your Desktop change gradually during the day then do the following. First, go into the Desktop and Screensaver Pref Pane and make sure the drop down is set to “Automatic”:
Then head on over to the “General / Appearance” Pref Pane and select the “Auto” setting:
Once you do that the Desktop appearance will change to match whatever time of day it is:
In my case it was early in the morning so my whole screen lightened up. It was like night and day!
No big revelation here, but it is nice to have this capability of you operate in Dark Mode. I will be bringing more Catalina features as I discover them.