I'm confused about MonthGenitiveNames and MonthNames. There are month names as values of both, so what is the difference between MonthGenitiveNames and MonthNames.
Also why is there "blank" for a month? If you look at values of both, there are blank values. What is the reason for the blank in Month names?
Genitive names exist because some languages use a different case of nouns to express dates (genitive instead of nominative).
E.g. in Polish nominative for January is "styczeń" but to express a date 2 January you need to use genitive "2 stycznia".