I would like to have more details to go to Jiuzhaigou from Guangyuan by bus.

I will arrive from Xian to Guangyuan at 07AM (May 2013) and i would like to take a bus at 08 or 09 am to go directly to the valley.
Do you know timetable between Guangyuan and Jiuzhai ? i heard that there was 11 hours between these two cities, is it true ?

Thanks a lot.