How to get started with localizing. Especially on localizing calander systems

I am a dev that is interested in helping out with localization projects specifically that of the Amharic language and Ethiopian Calendar. I think there is a preliminary support for Amharic language in Fedora Workstation (i.e. through gnome and translation of words) but one of the problem in advocating opensource in a country like Ethiopia is the lack of localized work flow. We use a Calendar system of our own that works as a similar to the Coptic Calendar and the Julian Calendar but with its own offsets, leap years and holiday calculations. The calendar system has been here for more than a thousand years and it is the main calendar system used for work, schooling and civil stuff. Because of that there is a whole lot of cottage industry in writing plugins for proprietary software to deal with this stuff. Even telling time becomes a pain because we count ours from sun rise not midnight(officially). So I am wondering if there is a way to localize that and if any body has had any experience with dealing with such things. I have some experience in the coding side of thing and I am willing to put in the work. I am just asking for help in the