query: #Dates before year 1 with precision >8: year, month, day
  #added 2016-08-07, Jura1
  SELECT ?item ?itemLabel (?date as ?GregorianDate) (CONCAT(str(1+YEAR(?date)*-1), " BC") as ?yearBC) ?dateprec ?dateprecisionLabel ?inputcalendarmodelLabel
  {
    {  SELECT ?item ?date (xsd:decimal(?precision) as ?dateprec) ?inputcalendarmodel
      {
        ?item p:P813 ?d .
              ?d psv:P813 ?datevalue .
          ?datevalue wikibase:timeValue ?date .             FILTER(?date < "+1-00-00T00:00:00Z"^^xsd:dateTime)
        ?datevalue wikibase:timePrecision ?precision .     FILTER(?precision > 8)
        ?d wikibase:rank ?rank .              FILTER(?rank != wikibase:DeprecatedRank)
        ?datevalue wikibase:timeCalendarModel ?inputcalendarmodel .
      }
          LIMIT 5000
      }
      ?dateprecision wdt:P2803 ?dateprec
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en,en,la" }
  }
  ORDER BY DESC(?date)