Hi @fabianc7 i know this is a 2yo post but, i tried your fix on ps 1.6.1.16 and it doesnt work, did you also change 'Product available date' column?.
I added all my 100 products with dates like this 2017-08-17 00:00:01, 2017-08-17 00:00:02, 2017-08-17 00:00:03 and so on i it didnt work.
I saw the demo csv and it just shows dates without times for both 'Product available date' and 'Product creation date' but i dont know if that could work.