I.e., importing a CSV field like "1970-01-01T00:00:45.890622" as "Date (YMD)"
should not truncate .890622 to .891.

Change-Id: I8d17ce54f63c3c4e68b8f90c63b6d1bb28bee67b
Reviewed-on: https://gerrit.libreoffice.org/63459
Tested-by: Jenkins
Reviewed-by: Eike Rathke <erack@redhat.com>