I am not your bro , bud . <| sep |> Hours , minutes and so on are countable , but they are also predominantly used as a continuous as opposed to discrete quantity . Compare The sonata lasts seventeen minutes . and This superhero movie has three memorable minutes the first is about halfway in , the second is at the 60 minute mark , and the third comes at the end . The first sentence implies more about the minutes than just the fact that there are seventeen of them it also implies that they follow each other . It indicates duration , a stretch of time . You ' re not so much counting minutes as measuring them off . It ' s also assumed to be a roundedoff quantity a sonata that last 16 minutes and 40 seconds , or 17 minutes and 20 seconds , could also be described as a sonata that lasts 17 minutes . In the second sentence , the three minutes are just that three separate minutes which are counted , but don ' t occur in sequence . This sentence is unusual and possibly a bit weird to read . So the reason less sounds more natural than fewer is because almost always , hours , minutes and so on are used to refer to an interval of time , rather than to a set of hours or minutes . This is also the reason we say , Five hours is a long time and not Five hours are a long time . You can see the same principle at work with money Five dollars is a lot of money . Five dollars were lying in the streets . I picked up one of them . This book can be yours for less than 12 dollars . That ' s right , only $ 11 . 99 ! I know he has fewer than 10 dollars , but I don ' t know how many dollars he has .