xref: /freebsd/usr.sbin/tzsetup/tzsetup.8 (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1.\" Copyright (c) 1996 Wolfram Schneider <wosch@FreeBSD.org>. Berlin.
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25.\" $FreeBSD$
26.Dd January 24, 1996
27.Dt TZSETUP 8
28.Os FreeBSD
29.Sh NAME
30.Nm tzsetup
31.Nd set local timezone
32.Sh SYNOPSIS
33.Nm
34.Op Fl n
35.Op Ar default
36.Sh DESCRIPTION
37The
38.Nm
39program reads a database of timezone information and presents a menu
40allowing the user to select a specific zone without knowing the details
41of the database layout.  The selected zone is installed as the system
42default zone.
43.Nm
44also determines whether any adjustment is necessary for systems where
45the hardware clock does not keep
46.Tn UTC .
47.Pp
48The following option is available:
49.Bl -tag -offset indent -width Fl
50.It Fl n
51Do not create or copy files.
52.El
53.Pp
54It is possible to short-circuit the menu system by specifying a
55.Ar default
56on the command line; this is intended mainly for pre-configured
57installation scripts.
58.Sh TIMEZONE DATABASE
59The contents of the timezone database are indexed by
60.Pa /usr/share/zoneinfo/zone.tab .
61This file lists, for each timezone data file, the
62.Tn ISO
633166 territory code, approximate geographical coordinates
64.Pq in Tn ISO No 6709 format ,
65and location within the territory.
66.Pp
67The maintainers of the database maintain the following policies:
68.Bl -enum -offset indent
69.It
70At least one zone for every country or inhabited geographical territory.
71.It
72One zone for every distinct, documented timezone history since the
73beginning of the
74.Ux
75epoch (January 1, 1970,
76.Tn GMT ) .
77.It
78Each zone is named for the most populous city therein.  (Where possible,
79the database includes pre-1970 history for its city.)
80.El
81The source code to the database
82.Pq Pa /usr/src/share/zoneinfo/[a-z]*
83contains many additional comments and documentation references for the
84historically minded.
85.Sh BUGS
86Programs which are already running when
87.Nm
88creates or updates
89.Pa /etc/localtime
90will not reflect the updated timezone.
91When the system is first configured for a
92.Pf non- Tn UTC
93hardware clock, it is necessary to run
94.Xr adjkerntz 8
95(which normally happens as a part of system startup) in order to update
96the kernel's idea of the correct timezone offset.
97.Sh FILES
98.Bl -tag -width /usr/share/zoneinfo/zone.tab -compact
99.It Pa /etc/localtime
100current time zone file
101.It Pa /etc/wall_cmos_clock
102see
103.Xr adjkerntz 8 .
104.It Pa /usr/share/misc/iso3166
105mapping of
106.Tn ISO
1073166 territory codes to names
108.It Pa /usr/share/zoneinfo
109directory for zoneinfo files
110.It Pa /usr/share/zoneinfo/zone.tab
111mapping of timezone file to country and location
112.El
113.Sh SEE ALSO
114.Xr date 1 ,
115.Xr adjtime 2 ,
116.Xr ctime 3 ,
117.Xr timezone 3 ,
118.Xr tzfile 5 ,
119.Xr adjkerntz 8 ,
120.Xr zdump 8 ,
121.Xr zic 8
122.Sh DISCLAIMER
123The representation of certain localities as being associated with certain
124countries and/or territories is for the purposes of identification only,
125and does not imply any endorsement or rejection on the part of the
126.Fx
127Project of the territorial claims of any entity.
128