How to fix time in S9?

Hi:

My Resmed S9 time is off by about 15 minutes, making trouble for correlating the data graphs with my sleep logs.

How can I fix this?

Thanks.

There is a clock you can set in the S9 clinical setup menu.
http://www.apneaboard.com/resmed-s9-cpap-setup
Under options selection

Thanks.

Don't change the S9 clock shortly after turning the machine off. Just before bedtime is probably best.

S9s get snotty about resetting all the old data when you change the clock if you're trying to "go back in time" or some such.