xref: /freebsd/usr.sbin/tzsetup/tzsetup.8 (revision bb897a8710b86716b40c490bde8e909c9af48760)

.\" Copyright (c) 1996 Wolfram Schneider <wosch@FreeBSD.org>. Berlin.
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.\" $FreeBSD$
.Dd January 24, 1996
.Dt TZSETUP 8
.Os FreeBSD
.Sh NAME
.Nm tzsetup
.Nd set local timezone
.Sh SYNOPSIS
.Nm tzsetup
.Op Fl n
.Op Ar default
.Sh DESCRIPTION
The
.Nm
program 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.
.Nm
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 n
Do not create or copy files.
.El
.Pp
It is possible to short-circuit the menu system by specifying a
.Ar default
on the command line; this is intended mainly for pre-configured
installation scripts.
.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
.Pq in Tn ISO No 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 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.
.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
.El
.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
.Tn FreeeBSD
Project of the territorial claims of any entity.