This is a linked open data (LOD) about date and time. "29 טבת 5781" is a date of Hebrew Calendar-TEST (Calendar ID: 104.1).
http://datetime.hutime.org/calendar/104.1/date/29_טבת_5781
hcal:104.1/date/2459227.5
hcal:104.1/date/29_טבת_5781
hcaldate:2459227.5
hcaldate:29_טבת_5781