Pre-order date format

Hi,

We use your pre-order plugin. I import dozens of products at a time using a CSV file, but I can’t figure out what format I need to use import the pre-order date in the CSV file.

For example I setup a product with a pre-order date of 19/09/2023 and when I export it it shows a figure in ‘Meta: _wpro_date’ of ‘1695121200’

I can’t figure out what formula I need to use to import the pre-order using the CSV file