How long before you know if this is your area?

Do you think three months out of a six month orientation is long enough to decide if you like a job? It started out great but the longer I go the less I like it. Also several things that were told to me during the interview like work schedule, call outs, working over, etc were not true. I should've known if something sounds too good to be true it probably is but I was very hopeful. They way it is (instead of the way it was portrayed) will not work well with my family schedule once I'm out of orientation. I don't want to burn any bridges though. Is it better to stick in there and finish the orientation and just see or would it fare better to tell them this isn't working for me and move on? I don't know which decision would be best-I don't want to make the employer mad because I do appreciate them giving me a chance. If I do finish the orientation and decide I still don't like it do you think they would let me go per diem? I just keep hoping the longer I do it the more I'll like it but it seems the opposite is happening. I just don't know what to do. Thanks for any insight!