fdo#70674 adapt wizard code to incompatible Date/Time API change

Change-Id: I0338777bf46c10f6082c7eb3886883e92952eb99
Reviewed-on: https://gerrit.libreoffice.org/6482
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>