I noticed this related question that briefly discusses Simchat Torah, but it mainly answers those that follow the annual cycle.
People following the annual cycle clebrate Simchat Torah on a Yom Tov (in Israel, on Shmini Atzeret, outside on 9th day after start of Succot.) It is celebrated on a Yom-Tov, specifically (i.e. - not on Shabbat (outside Israel), and there are hakafot, dancing, Chattan Torah, Breishit, etc.)
I am curious if those that followed the triennial cycle also had a "Simchat Torah" in the same fashion, i.e. - coinciding with a Yom Tov, and with hakafot, etc.? When would that have occurred? Was it on a fixed calendar date?