Abandon Carts

Is the cool off period the time the automation takes to send the first email? I am just trying this out and my order shows as an Abandon Carts in reports but it shows as Skipped under cool off period. I have looked at the settings and have set the cool off period to 1 day which seems to be the minimum period allowed. Is it possible to set this in hours? or maybe in fractions of a day.

Thanks

Nick