This is a linked open data (LOD) about date and time. "C.E. 0001 January 03" is a date of Julian/Gregorian Calendar (reformed in 1752) (Calendar ID: 101.2).
http://datetime.hutime.org/calendar/101.2/date/C.E._0001_January_03
hcal:101.2/date/1721425.5
hcal:101.2/date/C.E._0001_January_03
hcaldate:1721425.5
hcaldate:C.E._0001_January_03