TZINIT(8)

NAME
tzinit - initialize kernel time keeping variables

SYNOPSIS
tzinit [ OPTIONS ]

DESCRIPTION
Tzinit sets or inquires the FreeMiNT kernel time-keeping variables. Run with no options, tzinit will display the contents of all relevant kernel time keeping variables. Given the appropriate options will make tzinit change a subset of these variables.

Tzinit will examine the environment to analyse the settings for the local timezone. This will be done with the facilities provided by the standard programming library. The MiNTLib and the GNU libc will do this by analysing the contents of the environment variable TZ (see environ(5) for details). If this variable is not set (which is recommended) a system-wide default timezone will be read from the file /usr/etc/zoneinfo/localtime to find out the offset to Greenwich Mean Time for the local timezone. If set to an empty value, the time zone "GMT" (Greenwich Mean Time) is assumed. If the contents of TZ starts with a colon the rest of the contents of the variable is interpreted as the name of a file to be examined for time zone settings instead of /usr/etc/zoneinfo/localtime. If none of the above applies the variable is parsed according to the syntax described by POSIX. If no rules for summertime (also known as Daylight Savings Time DST) were supplied a system-wide default file /usr/etc/zoneinfo/posixrules is examined.

The program should be invoked in the startup-sequence of the FreeMiNT system, as early as possible because it may cause the kernel clock to make leaps which can lead to undesirable effects (this can actually only occur if you use tzinit to make your kernel clock tick in local time). It is probably best to run tzinit from your mint.cnf(5) file.

OPTIONS

These options are available:

-h, --help
    Print a short usage summary and exit.

-l, --localtime
    At system startup the FreeMiNT kernel runs in UTC clockmode. That means that the time value supplied by the hardware clock facilities is interpreted as a time in Universal Time Coordinated (UTC). Given tzinit the option --localtime will change the kernel's behavior so that hardware date and time is interpreted as a time value in local representation instead. This facility is useful when running other old-fashioned operating systems beside FreeMiNT on the same machine which always interprete the hardware time as a local time.

-s, --silent, --quiet
    This option disables all diagnostic output except error messages.

-t TIMEZONE, --timezone=TIMEZONE, --tz=TIMEZONE
    By default the tzinit program will inquire the current settings for the local timezone by examining the environment variable TZ. This option lets you override the value given in the environment.

-n, --no-timezone, --no-tz
    Removes an existing definition for the variable TZ from the environment. This option may be useful in situations where you can't unset environment variables (like when running from mint.cnf or the like). Note that unsetting the TZ environment variable has not the same effect as setting it to the empty string (see above for details).

-u, --utc, --gmt
    Set (or reset) the kernel clock mode to the default (hardware time is interpreted as Universal Time Coordinated UTC).

-V, --version
    Display a short version information and exit.

-v, --verbose
    Enable verbose diagnostic output (default). The tzinit program will display the contents of all relevant kernel time-keeping variables.

FILES

/usr/share/zoneinfo/localtime

/usr/share/zoneinfo/posixrules

AUTHOR
The tzinit program was written by Guido Flohr <guido@freemint.de>. It is part of the MiNTLib project and available under the COPYMINT license.

STANDARDS
Pure anarchy, no standard knows this program.

SEE ALSO
Tsettimeofday(2), Ssystem(2), tzset(3), tzsetwall(3), ctime(3), environ(5), tzfile(5), zic(8), zdump(8)