freebsd/usr.sbin/tzsetup/tzsetup.8

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.Dd July 4, 2009
.Dt TZSETUP 8
.Os
.Sh NAME
.Nm tzsetup
.Nd set local timezone
.Sh SYNOPSIS
.Nm
.Op Fl nrs
.Op Fl C Ar chroot directory
.Op Ar zoneinfo file | zoneinfo name
.Sh DESCRIPTION
The
.Nm
utility reads a database of timezone information and presents a menu
allowing the user to select a specific zone without knowing the details
of the database layout.
The selected zone is installed as the system
default zone.
The
.Nm
utility also determines whether any adjustment is necessary for systems where
the hardware clock does not keep
.Tn UTC .
.Pp
The following option is available:
.Bl -tag -offset indent -width Fl
.It Fl C Ar chroot directory
Open all files and directories relative to
.Ar chroot directory .
.It Fl n
Do not create or copy files.
.It Fl r
Reinstall the zoneinfo file installed last time. The name is obtained from
.Pa /var/db/zoneinfo .
.It Fl s 
Skip the initial question about adjusting the clock if not set to
.Tn UTC .
.El
.Pp
It is possible to short-circuit the menu system by specifying the
location of a
.Ar zoneinfo file
or the name of the
.Ar zoneinfo name
on the command line; this is intended mainly for pre-configured installation
scripts or people who know which zoneinfo they want to install.
.Sh TIMEZONE DATABASE
The contents of the timezone database are indexed by
.Pa /usr/share/zoneinfo/zone.tab .
This file lists, for each timezone data file, the
.Tn ISO
3166 territory code, approximate geographical coordinates
(in
.Tn ISO
6709 format),
and location within the territory.
.Pp
The maintainers of the database maintain the following policies:
.Bl -enum -offset indent
.It
At least one zone for every country or inhabited geographical territory.
.It
One zone for every distinct, documented timezone history since the
beginning of the
.Ux
epoch (January 1, 1970,
.Tn GMT ) .
.It
Each zone is named for the most populous city therein.
(Where possible,
the database includes pre-1970 history for its city.)
.El
The source code to the database
.Pq Pa /usr/src/share/zoneinfo/[a-z]*
contains many additional comments and documentation references for the
historically minded.
.Sh FILES
.Bl -tag -width /usr/share/zoneinfo/zone.tab -compact
.It Pa /etc/localtime
current time zone file.
.It Pa /etc/wall_cmos_clock
see
.Xr adjkerntz 8 .
.It Pa /usr/share/misc/iso3166
mapping of
.Tn ISO
3166 territory codes to names.
.It Pa /usr/share/zoneinfo
directory for zoneinfo files.
.It Pa /usr/share/zoneinfo/zone.tab
mapping of timezone file to country and location.
.It Pa /var/db/zoneinfo
saved name of the timezone file installed last.
.El
.Sh EXAMPLES
Normal usage, to select the right zoneinfo file via the dialog-based
user interface:
.Dl # tzsetup
Install the file
.Pa /usr/share/zoneinfo/Australia/Sydney :
.Dl # tzsetup /usr/share/zoneinfo/Australia/Sydney
Install the zoneinfo file for Australia/Sydney, assumed to be located
in
.Pa /usr/share/zoneinfo :
.Dl # tzsetup Australia/Sydney
After a reinstall of the zoneinfo files, you can reinstall the
latest installed zoneinfo file: (as specified in
.Pa /var/db/zoneinfo )
.Dl # tzsetup -r
.Sh SEE ALSO
.Xr date 1 ,
.Xr adjtime 2 ,
.Xr ctime 3 ,
.Xr timezone 3 ,
.Xr tzfile 5 ,
.Xr adjkerntz 8 ,
.Xr zdump 8 ,
.Xr zic 8
.Sh DISCLAIMER
The representation of certain localities as being associated with certain
countries and/or territories is for the purposes of identification only,
and does not imply any endorsement or rejection on the part of the
.Fx
Project of the territorial claims of any entity.
.Sh BUGS
Programs which are already running when
.Nm
creates or updates
.Pa /etc/localtime
will not reflect the updated timezone.
When the system is first configured for a
.Pf non- Tn UTC
hardware clock, it is necessary to run
.Xr adjkerntz 8
(which normally happens as a part of system startup) in order to update
the kernel's idea of the correct timezone offset.