Study the effects of the sun's path on your projects.
The first step for accurate shadow studies is to set your project location.
Once you've set your location and optionally imported a satellite image, model your project including building context, and shading elements like louvers and trees.
Turn shadows on in the Sun + Shadows flyout at the top of the application (this can also be done in Visual Styles).
From here, you can adjust the time of day and day of year. The default year is shown as 2000 - don't worry, this doesn't affect the accuracy of the sun shading study.
You can also toggle the Sun Editor from this panel (or use shortcut DR), which provides a graphical display of the sun's location in space:
The Sun Editor will move with the camera, so you may have to adjust your zoom level and/or camera orientation to get the widget in a position that makes sense relative to the design you're studying.