Hi glad you are enjoying the trip, stick with it we have seen some amazing scenery along the route.
Make sure that you have all the options under General > Data > Data Connection set to on or at least Online Functionality, Bing Data World Graphics, Live Weather, Multiplayer.
Make sure that you are connected to a Server i.e. Status online and a server populated.
When you set up your flight Conditions under Multiplayer select all players.
Under Weather and Time select Live weather.
Load up the flight and then check to see if you can open the weather tool bar from the top of the screen. If you are on Live Weather everything will be greyed out in the window, under the selection at the top is a blue line with the time written underneath it to the right, you should be able to adjust the time of day using the slider.