Does my employer have to accommodated me if i choose to go to college to study another career?

Im currently in full time employment working continental shifts 6am-6pm(4 days on 4 days off) the job pays ok but is not somewhere i want to be in 5-10 years time. so ive looked into doing a night course doing a electrical course its not work related but something id like to do in the future. the course is 6pm-9pm 2 days a week so some days it will coincide with me being at work so ive asked the supervisor if it was possible if on the days i have college if i could leave half an hour early to attend college and that id make the time back, he said that shouldn't be a problem but would have to ask the manager. the manager said it wouldn't be possible as its not work related. so i want to no if there's any regulation that state they have to accommodated the employee in further education, i really want to do this course but wanna stay in a decent paid job whilst doing it is there any way round this any information on this would be great!Thank u