Mar bar Rav Ashi (Tabyomi) (Hebrew: מר בר רב אשי, read as Mar bar[son of] Rav Ashi; other: Hebrew: טביומי, read as Tabyomi or Tavyomi, lit. good days) was a JewishAmora sage of Babylon, of the seventh generation of the Amora era. He was the son of Rav Ashi, headed the academy of Sura city in its suburb of Matha-Mehasia, and would sign his name as Tabyomi, which was either his first name or his nickname. He was appointed to head the academy in 455 AD (ד'רט"ו, Hebrew calendar), 28 years after his father died, and served in that job for 13 years, until he himself died on Yom Kippur of the year 467 AD (ד'רכ"ח, Hebrew calendar). His father, who was his Teacher par excellence, and whom he had delivered Halakhic statements on his authority, had a life work of arranging the BabylonTalmud, a life work that was to be continued by his son.