After a 4-month break in the game, I logged in and … big disappointment: when I loaded the saved flight, to continue it, there is still no icon to freely change the weather and time of day during the flight … and i cant switch on this icon because switch is grey 
. Massacre.
Are you on Live Mode when you fly it? Live mode can’t change weather or time of day.
No, I planned a flight, I flew over an hour, I could change the weather and time normally, saved the game, quit the game. When I entered the game again and loaded a saved game, I do not have an icon to change the weather and time. In the toolbar settings I can’t turn it on because it’s gray. I play in the same mode all the time.