If you are working in a Big 4 CPA firm, the normal working hour is usaually from 8:30 am to 11:00 pm.
My own real experience was that I had to work until 3:00 am for an entire month during the deadline period. Whether it is worthy or not, it all depends on how much you love this career. If your sole intention is to work for moeny, then you would better forget it. Your salary is never commensurated to your workload, let alone the health problems that you may suffer during the endeavor. Amongst all the other things, what I hated most was filling the timesheet.