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rtc(1m) [netbsd man page]

rtc(1M)                                                   System Administration Commands                                                   rtc(1M)

rtc - provide all real-time clock and GMT-lag management SYNOPSIS
/usr/sbin/rtc [-c] [-z zone-name] DESCRIPTION
On x86 systems, the rtc command reconciles the difference in the way that time is established between UNIX and MS-DOS systems. UNIX systems utilize Greenwich Mean Time (GMT), while MS-DOS systems utilize local time. Without arguments, rtc displays the currently configured time zone string. The currently configured time zone string is based on what was last recorded by rtc-z zone-name. The rtc command is not normally run from a shell prompt; it is generally invoked by the system. Commands such as date(1) and rdate(1M), which are used to set the time on a system, invoke /usr/sbin/rtc -c to ensure that daylight savings time (DST) is corrected for properly. OPTIONS
-c This option checks for DST and makes corrections if necessary. It is normally run once a day by a cron job. If there is no RTC time zone or /etc/rtc_config file, this option will do nothing. -z zone-name This option, which is normally run by the system at software installation time, is used to specify the time zone in which the RTC is to be maintained. It updates the configuration file /etc/rtc_config with the name of the specified zone and the current GMT lag for that zone. If there is an existing rtc_config file, this command will update it. If not, this command will create it. FILES
/etc/rtc_config The data file used to record the time zone and GMT lag. This file is completely managed by /usr/sbin/rtc, and it is read by the kernel. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Architecture |x86 | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ SEE ALSO
date(1), rdate(1M), attributes(5) SunOS 5.10 3 Oct 2003 rtc(1M)

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zdump(1M)						  System Administration Commands						 zdump(1M)

zdump - time zone dumper SYNOPSIS
zdump [-v] [-c cutoffyear] [zonename...] DESCRIPTION
The zdump command prints the current time for each time zone (zonename) listed on the command line. Specify zonename as the name of the time zone database file relative to /usr/share/lib/zoneinfo. Specifying an invalid time zone (zonename) to zdump does not return an error, rather zdump uses GMT. This is consistent with the behav- ior of the library calls; zdump reflects the same behavior of the time routines in libc. See ctime(3C) and mktime(3C). OPTIONS
The following options are supported: -v Displays the entire contents of the time zone database file for zonename. Prints the time at the lowest possible time value; the time one day after the lowest possible time value; the times both one second before and exactly at each time at which the rules for computing local time change; the time at the highest possible time value; and the time at one day less than the highest possible time value. See mktime(3C) and ctime(3C) for information regarding time value (time_t). Each line of output ends with isdst=1 if the given time is Daylight Saving Time, or isdst=0 otherwise. -c cutoffyear Cuts off the verbose output near the start of the year cutoffyear. EXIT STATUS
The following exit values are returned: 0 Successful completion. 1 An error occurred. FILES
/usr/share/lib/zoneinfo Standard zone information directory ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ SEE ALSO
zic(1M), ctime(3C), mktime(3C), attributes(5), environ(5) SunOS 5.10 19 May 1997 zdump(1M)
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