biblatex-dm.cfg

\DeclareDatamodelFields[type=field, datatype=date, skipout]{urlupdate}
\DeclareDatamodelFields[type=field, datatype=integer]{
  urlupday,
  urlupendday,
  urlupendmonth,
  urlupendyear,
  urlupmonth,
  urlupyear}

\DeclareDatamodelEntryfields{
  urlupdate,
  urlupday,
  urlupendday,
  urlupendmonth,
  urlupendyear,
  urlupmonth,
  urlupyear}

\endinput