handle empty dates
handle empty dates

brendo/datetime,alexbirukov/datetime,brendo/datetime,jonmifsud/datetime,fdanielsen/datetime,jonmifsud/datetime,klaftertief/datetime,genome-vendor/datetime,genome-vendor/datetime,benesch/datetime,benesch/datetime,genome-vendor/datetime,creativedutchmen/datetime,alexbirukov/datetime,alexbirukov/datetime,domsammut/datetime,domsammut/datetime