No more my language support in Photos calendar

Well, I've used Photos calendar project feature for years. Since High Sierra and Photos v.3.0 I can’t set my language to show dates in my language (lithuanian) anymore. I can set region and language to lithuanian, but it doesn’t reflect on a Photos calendar. I don’t want to set the language for the whole UI, just calendar date names. Prior to High Sierra I could do it just easily, everything worked fine. Anyone experienced this problem, please share your knowledge. Otherwise… no more beautiful calendars for the family this year… 😟

Thanks a lot,

Saul