[basex-talk] add-dayTimeDuration-to-date

Hello, I am trying to add dates and duration through BaseX, in conformance with http://www.w3.org/TR/xpath-functions-30/#func-add-dayTimeDuration-to-date. However, BaseX interpreter does not recognize the function add-dayTimeDuration-to-date, nor op:add-dayTimeDuration-to-date. Did I misunderstood something ? Thanx for your answer, Cheers, Jean-Marc