There is a setting for GR"A or M"A, which are different methods for calculating "***** for halakhic times". I think I've figured out that GR"A is גָּאוֹן רַבֵּנוּ אֵלִיָּהוּ. But I can't find neither any calendar intercalation nor related contribution associated with him nor what M"A might stand for, nor what intercalation that would be. I also don't know which (if either) would be תימני (or closest to it).