Hours Required at truck Driving School

Is there a certain amount of hours that truck driving schools in California require before you can take your test for class A. The reason I ask is because I'm getting ready to start school and one of the schools I'm thinking about going to is 4 hours a day for one month witch is 80 hours and all other schools I have checked out are 8 hours per day for a month equaling 160 hours. Thanks for any help!