This is a linked open data (LOD) about date and time. "C.E. 1807 January 09" is a date of Gregorian Calendar (Calendar ID: 2.1).
http://datetime.hutime.org/calendar/2.1/date/C.E._1807_January_09
hcal:2.1/date/2381060.5
hcal:2.1/date/C.E._1807_January_09
hcaldate:2381060.5
hcaldate:C.E._1807_January_09