What century did Shulgi reign for 48 years?
Babylonian calendar The Babylonian calendar was a lunisolar calendar with years consisting of 12 lunar months, each beginning when a new crescent moon was first sighted low on the western horizon at sunset, plus an intercalary month inserted as needed by decree. The calendar is based on a Sumerian (Ur III) predecessor preserved in the Umma calendar of Shulgi (c. 21st century BC).
Shamshi-Adad II Shamshi-Adad II or Šamši-Adad II, inscribed "Šam-ši-"IM, was an Old Assyrian king who ruled in the mid-second millennium, ca. 1585-1580 BC (short chronology). His reign falls within the "dark age" period of Assyrian history where written records are scarce.