I find this link helpful: moment/moment#3899
With that information I managed to insert Serbian Latin as well.
I change that suffix "...sr_rs_latn" to "...sh"

Now I need answer how to translate months from java library? java.text.DateFormatSymbols
In some of the languages (bs, mk, al, me) I use in keycloak the localization is not right!
Date format is "en" and translations for months are English, also "bs" language have M08 instead of August.
Does anyone have opinion how to translate months or set right locale?

I google and I find answer https://stackoverflow.com/questions/1038570/how-can-i-convert-an-integer-to-localized-month-name-in-java
But I have Docker and keycloak on that docker... I can not change keycloak files directly...