Every clock app I have seen will not adjust the system clock. Apple in their infinite wisdom doesnt let anything touch the system clock.
In the Settings menu under General>Date&Time is an option "Set Automatically", but it doesn't say how it's set.
As an experiment, I turned Set Automatically to OFF and manually changed the time to about 8 minutes slow. I then turned off 3G and did a sync and the time did not change. I turned on 3G and the time changed to the correct time after about 1 second. This with Set Automatically still off. I'm guessing the Automatic option sets according to physical location. I guess if you change time zones, the time will change.
Mine is wifi only and it does no auto update just a daily gain of 15 secs a day or so. Not a huge deal but I would expect better
The iPad time is synced with the PC time
I have not noticed my clock drifting. Any time I have compared it to my WWV clock it has been within a second of it even though it might not have been synced for days.
I have a 3G model and have always assumed that it was syncing with the AT&T network.
A seed hidden in the heart of an apple is an orchard invisible.
Typo assist by iPad
Whenever I sync my iPad with my Mac, the clock is adjusted.
Therefore it works for me.