My girlfriend is going to travel to the Netherlands with me on March 1st for a 2 weeks visit.
She has a Multi-C Schengen visa for 1 year which started on April 24th 2014 and ends on May 7th 2015.

Her passport however expires on August 22nd 2015.

How many remaining months does a passport have to be valid for before entering a Schengen country? Is that 3 or 6 months?

The passport expires 5 months and 23 days after she enters the country.

Thanks

A third country nationals passport must be valid for at least three months after the intended departure date from the Schengen Area.

So if your girlfriends visit is on for two weeks after her March arrival, and she has evidence of this, she should be fine.

Para 5 (I) .....its validity shall extend at least three months after the intended date of departure from the territory of the Member States. In a justified case of emergency, this obligation may be waived;

I double-checked and indeed there's nothing to worry about. She'll renew her passport when we return.

Thanks for the info old man.