[ntp:questions] Can i control the NTP Sync?
david at ex.djwhome.demon.co.uk.invalid
Wed Aug 13 06:50:47 UTC 2008
> machnes) the machine time is ALWAYS UTC. time routines do the translation
> using a file called /etc/localtime. On windows it is more difficult, since
Not all Unixes use the Olson package and some may use a different
location for this file. Some Unixes, in current use, encode the rules
in an environment variable, which needs to be changed when the rules
change (but not when the clocks change), and thus an application
restart. Earlier ones only allowed the base timezone offset to be
changed but had the, historic, US timezone rules hardcoded. I think the
original Unix did timezones only the kernel.
You will have some problems in exchanging media between Unix systems if
you don't run them on UTC, as file timestamps are stored in the POSIX
encoding of UTC and converted to local time by the ls command, etc.
> Microsoft has never heard of timezones, so you have to kludge it yourself.
Microsoft have supported timezones since Windows 9x or earlier and have
reasonably proper support since Windows NT. For legacy reasons, they
store wall clock time in the RTC hardware. Windows encodes the rules in
the registry and the registry needs updating when the rules change, but
I don't think you need an application restart. (Both the older Unix
system and NT are limited to two changes and two offsets per year.)
> Exactly how your machine or your implimentation of ntp kludges it I do not
More precisely, you always need to specify what OS you are using. Not
specifying in an NTP context tends to imply Linux, but Linux tends to be
leading edge and any recent one will use the Olson package.
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