The model location specifies a real-world location for the purposes of simple Revit-based analyses, such as shadow studies.
Specify the model's location using the Location tool
on the Manage tab. You can select the nearest city from a list or use an Internet mapping service to specify a street address or the latitude and longitude.

Revit uses the location as follows:
When you log in as an Autodesk subscriber and specify a location, you can select a nearby weather station to use in analyses.
The model location does not affect the following: