This is a linked open data (LOD) about date and time. "C.E. 1679 February 01" is a date of Julian/Gregorian Calendar (reformed in 1752) (Calendar ID: 101.2).
http://datetime.hutime.org/calendar/101.2/date/C.E._1679_February_01
hcal:101.2/date/2334343.5
hcal:101.2/date/C.E._1679_February_01
hcaldate:2334343.5
hcaldate:C.E._1679_February_01