In Lithuanian the month need to be in nominative case if the format does not include a day, and in genitive case if the format does include a day. Could you please enable skeletons such as yMMMM (http://st.unicode.org/cldr-apps/v#yMMMM) and MMMM/M for Survey Tool translations in Lithuanian locale (similarly as in Russian locale), in order to map to patterns as "y LLLL" and "LLLL–LLLL".
Verified "lt" gregorian months have genitive in the format names (MMM+) and nominative in the stand-alone names (LLL+)
The changes here do two things for the lt gregorian formats (not necessary for non-gregorian since we don't currently have the nominative vs genitive distinction in months, etc.):
Ensure that month names without days are in nominative (LLL+), month names with days are in genitive (MMM+)
Separate availableFormats and intervalFormats for MMM skeletons vs MMMM skeletons. This is requested here but also necessary to implement : (don't use abbreviated month names)