Scheduled triggering and dependencies

The scheduled build trigger has the following option:

"Trigger build only if there are pending changes"

If I select this, will it only build on changes to the VCS associated with this build?  Or will it build if  there are changes to snapshot dependencies too?  What I really want is for this to run every night if there is anything new that it should build, but I don't want this build to have to know any of the specifics of the snapshot dependencies.

Thanks,
-a