This is a linked open data (LOD) about date and time. "28/12/1122" is a date of Hijri Calendar-TEST (Calendar ID: 9103.2).
http://datetime.hutime.org/calendar/9103.2/date/28/12/1122
hcal:9103.2/date/2346036.5
hcal:9103.2/date/28/12/1122
hcaldate:2346036.5
hcaldate:28/12/1122