This is a linked open data (LOD) about date and time. "C.E. 49720 November 02" is a date of Gregorian Calendar (Calendar ID: 2.1).
http://datetime.hutime.org/calendar/2.1/date/C.E._49720_November_02
hcal:2.1/date/19881222.5
hcal:2.1/date/C.E._49720_November_02
hcaldate:19881222.5
hcaldate:C.E._49720_November_02