This is a linked open data (LOD) about date and time. "17 טבת 5780" is a date of Hebrew Calendar-TEST (Calendar ID: 104.1).
http://datetime.hutime.org/calendar/104.1/date/17_טבת_5780
hcal:104.1/date/2458862.5
hcal:104.1/date/17_טבת_5780
hcaldate:2458862.5
hcaldate:17_טבת_5780