They can make you view the videos not during normal working hours (e.g. in the evening, on weekends, etc.), *but* they have to pay you for watching them, if you are (as you indicate) hourly and the videos are mandatory (e.g. it's not that it's a good idea to watch them, because it will help you at work or help you get a promotion, but you can refuse to watch if you choose--rather, you *must* watch them). Anything that the employer requires you to do for its benefit, including watching training videos, is work, regardless of when you have to do it or the location (e.g. at home or offsite); hourly employees must be paid for all hours worked.