1password import from firefox csv: missing creation and last usage date

Hi, 

i only found a 4 year old discussion on this topic, which contains a link to another discussion which no longer exists.

I installed the latest version of 1 password and wanted to import the firefox passwords. I extracted and saved them as csv, the csv does hold fields for created and last used date. These are important to me so i can cleanup, but unfortunately these fields are not imported.

So how can i do this, i read something about first converting these timestamps inside the csv, but i am missing details.

thanks for your help.