signature of Date and Date::DateToDays is
(sal_uInt16 d, sal_uInt16 m, sal_Int16 y)
same types as css::util::Date members Day, Month and Year

Change-Id: Ifa35574d2d335f7bf816dd5209988f4eaf7c5ac2
Reviewed-on: https://gerrit.libreoffice.org/40462Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>