how do you define an action to in a set time delay?

Hello,
Working on iMac Sierra with Hazel latest versions.
Even after reading through the manual, I am unable to understand how to create a rule like 'delete all DMG files in my Download folder' (so far no problem), 'but carry out this action (rule) only one week after the file was downloaded'.
thanks very much in advance for your time and help
dorindon
Working on iMac Sierra with Hazel latest versions.
Even after reading through the manual, I am unable to understand how to create a rule like 'delete all DMG files in my Download folder' (so far no problem), 'but carry out this action (rule) only one week after the file was downloaded'.
thanks very much in advance for your time and help
dorindon