They are open at night, at least until EPCOT regular closing time. I've been there during the PM EMHs as well, but I'm not sure if they are always open during PM EMHs and how late into the EMHs they are usually open.
The Patisserie closes at the start of IllumiNations on non-EMH nights.
Last December on EMH night it closed at 11PM. Kringla, however, remained open until midnight. This was during Candlelight Processional so EMH was from 9:30 - 12:30 AM.