Adding Austrian German month names (Jänner and Feber) to the list of recognised lists of month names to allow localisation of dates in SDL Studio 2014

I frequently deal with Austrian German and German German dates in text and am having problems setting up the auto localisation option to also ensure that Jänner and Feber are recognised in SDL Studio 2014. In particular their recognition is important to stop sentence-based segmentation being thrown out. How can Jänner and Feber be added? Many thanks in advance.