[pkg-ntp-maintainers] Bug#415335: Allow to set time in slewed mode upon installation

[Stephen J. Turnbull]

I agree with David.  Resetting the system clock is a potentially
dangerous action.  Examples: make(1) will fail to rebuild targets
changed since the time correction but within the preexisting slew;
cron jobs will fire twice or not at all.  It should be done only at
the administrator's request.  Debconf should detect the slew, and say
something like

"I can reset your clock using NTP now.  Your current time is 11:17:03
JST; it will be reset by adding [subtracting] hh:mm:ss.  It is
possible that some applications will be adversely affected, such as
make and cron, but it is normally safe to reset time on a personal
workstation.  (Note: if the slew is over 5 seconds and you do not
reset now, ntpd will not adjust the time until you tell it to do so.)
Shall I reset the time now? [Yes] [No]"

In my case the slew was large: I live in Japan, made a fresh install
of Debian to a Dell box, and (for reasons that escape me) the Etch
installer didn't ask whether the hwclock was set to UTC or local time,
but simply assumed UTC.  Since Dell boxes (at least in Japan) come
with the clock set to local time, I ended up 9 hours (and 31.74+
seconds :-) in the future.  Yet installing ntp corrected that huge
slew without asking me!  9 hours is a long time to live without make ;-)

In my case, my intention was to run ntpdate immediately.  In a sense
this is convenient.  But I don't run Debian for convenience; I run it
because it's reliable and robust.  Where I'm willing to sacrifice
those properties for convenience, I run Ubuntu (or Mac OS X).  I hope
that Debian will continue to prefer robustness over convenience where
they conflict.

Thanks for your consideration.