The next release of Collect will include support for the Bikram Sambat (Nepali) calendar thanks to @alxndrsn and @Grzesiek2010.
@alxndrsn, you'll recall that long ago, we discussed doing this using a joda time chronology. By the time we got to it, that project had been frozen to further development. Oops! So instead we went with directly using your tried and tested library at https://github.com/medic/bikram-sambat. It is currently being imported from https://staging.dev.medicmobile.org/_couch/maven-repo
. Would you consider publishing it to Maven Central so we know it's in a permanent place? @yanokwa publishes JavaRosa so should be able to help if needed.