Hi Jack,
As promised I just set my 5817 against the time.gov watch. The time was 10:00 am PST.
However, there was no hacking available to me so I tried to fiddle a little to get the seconds to stop but I had some difficulty. Basically a tried to wind back and hold the seconds for a bit. Anyway I was able to get my setting three seconds behind the time.gov clock.
I will check the watch again in 24hours.
Bill
PS the gov clock claims to be accurate to 0.4 seconds which I hope is enough.