http://www.dailywritingtips.com/using-zeitgeist-coherently/ I don't usually like to answer with just a link, but I think that page explains it extremely well, so you should check there. I would agree with the author of the webpage that it is a hard word to use correctly even for native English speakers, so caution is advised.

plus this is german word, you know it will not have ordinary everyday meaning if it's borrowed from another language.