I do not get it…

Ok. I an trying to use this plugin. First what I have seen is a bug, where November month plugin named after “December”, December month as “January of next year”, – so you can see +1 month every time is shown.
Bit funny part is – after edition calendar (with a very few options because many of them PRO-only, phh…) I have to put two button: apply and save. No matter which button I have choose, – my calendar dis not save. So, what is point?