how to schedule a job every day

HI ALL:

                We need to create a job which run in 10:00PM every day,
                when set the interval to 'sysdate+1',it seem work fine. But
after a few day,
                there are two problem occur:
                1.the job execution time although approximately 10:00PM, but
incremental every day,like
                    day 1: 10:00PM
                    day 2: 10:05PM
                    day 3: 10:08PM
                 but we want the job run in 10:PM every day
                2.when we shutdown database in some day, and startup in
another day.
                    Suppose startup in 09:00AM,
                    we find the job's next_date would be altered to 09:00AM

                how can we solve these problem. Thanks in advance