import date format correct in magento 2

i’m tring to import a date field correct into the special_from_date and special_to_date field of products however for some reason the result is not correct.

I have this

-
008739-91-31
PROM18-00011
1
65.00
99.90
06-04-2018
09-30-2018

i try every format like d/m/y m/d/y y/m/d d-m-y m-d-y y-m-d
but the result is everytime different date but not correct.