My cousin lives in England. I'm so jealous. :(
Timetables -- or schedules, as they call them here -- vary from school to school, especially with all of the public school districts, private schools, and charters. The vast majority of schools in Los Angeles I know start at around 8 and 3:15 for public schools. They generally have 6 periods, meaning classes, each about 50 minutes, in addition to a set lunch period. There are passing periods in between classes to get from room to room. Sometimes, studious people have a 0 period to fit in more classes or grab an opportunity they wouldn't get otherwise; my sister takes a 0 period AP Economics class, and it starts at 7 am.
Schools that are charters like mine (I hate my school...it's really a big sham) can have wildly different schedules. The one I go to is a performing arts-/ robotics-focused school, so we have majors like in university and 8 or 9 periods (classes) a day, one of which should be a lunch hour. I am a music major with 8 periods so I start school at 8 and end at 4. I don't have a lunch because I scheduled my classes to fill up all 8 periods. The school is THAT boring. I have friends that go to other specialized schools that have block schedules (split classes between days) and some even start at 8:45.
Private schools generally have the best-built timetables. I'll give you links to the separate types of schools. :)
Public schools:
http://ecrhs.net/ecr.php?page=bells (high school)
http://www.lausd.k12.ca.us/Millikan_MS/calendar/bellschdl.html (middle school)
http://www.calabasashigh.net/ (look for the bell schedule on the left)
Charter schools:
http://www.ht-la.org/apps/bell_schedules/
http://www.champscharter.org/apps/bell_schedules/
http://lachsa.net/apps/bell_schedules/
Private schools:
http://www.hw.com/studentlife/tabid/2110/Default.aspx
http://www.marlboroughschool.org/podium/default.aspx?t=109602
:)