[ntp:questions] Using both Server and Peer in ntp.conf

[Hal Murray]

>How many minutes, hours, or days of "holdover" with reasonably correct 
>time you may get depends on the quality of the local clock, the 
>stability of the temperature, the phase of the moon and the whims of the 
>gods!

We can at least do a bit of arithmetic.

There are 86400 seconds in a day.  If your clock is off
by 11 ppm, it will drift 1 second per day.

If your machine is in an airconditioned machine room, the
average temperature is probably pretty stable.  I'd guess
a second per week would be conservative.

If your machine is in an environment with poor temperature
regulation, the day to day average temperature is probably
the important consideration.

-- 
These are my opinions, not necessarily my employer's.  I hate spam.