Does the train strike in Italy end at the time announced?

There is a train strike scheduled on July 7th 9:00pm (21:00) to July 8th 6:00pm (18:00). I need to get from Florence to Milan on the 8th. There are no guaranteed trains leaving from Florence. Do the strikes actually end at the listed time? If I book a ticket for a train at 18:25 is it going to be cancelled or just delayed while everything gets sorted? I don’t mind a delay at all, as long as it’ll still run and won’t be cancelled. Thank you!! First time navigating a train strike, wish me luck!