9 More Discussions You Might Find Interesting
1. AIX
Hello,
I like to set the CDT timezone, but it shows CST still even after I activated the DayLight Time
cat /etc/environment | grep TZ
TZ=CST6CDT
Now looking at date:
root@test8:/>date
Tue Dec 20 05:34:45 CST 2016
How can I make it from CST to CDT ?
thanks (5 Replies)
Discussion started by: filosophizer
5 Replies
2. UNIX for Advanced & Expert Users
We have an ancient Unix box from Siemens. Every year the system automatically changes the time for EST or DST. Unfortunately since the box is so old the dates that the times change are the old dates and not the current ones set during (I think) the Bush years.
When I have to set the time back... (3 Replies)
Discussion started by: jbcamel
3 Replies
3. AIX
Our aix unix box did not recognize daylight savings time since it was moved up. Could someone please give me the syntax to change the hour? I looked in man and couldn't find anything, or I missed it. I'm in 3rd grade so if you can, please provide specific instructions.
Thanks! (2 Replies)
Discussion started by: vbagwell
2 Replies
4. Solaris
I am running a SUN E450 on solaris (5.7). I have applied the DST patch and the system time is correct. However when users login the get the time wrong (+4 hours) (I am in EDT Zone). Does anyone know where a system wide variable for this could be set. (Root user gets the right time)
Frank (3 Replies)
Discussion started by: frankkahle
3 Replies
5. Solaris
Hello,
I've been looking at coming up with a time change on my Sun workstations since daylight savings time comes early this year. Someone at work told me that a sun patch is available if you have a maintenance contract. It was recommended to just set your systems to GMT time zone. How is this... (5 Replies)
Discussion started by: stocksj
5 Replies
6. UNIX for Dummies Questions & Answers
Hey guys,
How do i check and see if my server will automatically adjust itself for daylight savings?
Thanks! (6 Replies)
Discussion started by: kingdbag
6 Replies
7. Solaris
I have a solaris 8 server - and I need to ensure the daylight savings change properly but I dont think its set up correctly:
/usr/sbin/zdump -v -c 2005 $TZ
GB-EIRE Wed Oct 26 12:20:02 2005 UTC = Wed Oct 26 12:20:02 2005 GB isdst=0
GB-EIRE Fri Dec 13 20:45:52 1901 UTC = Fri Dec 13 20:45:52... (5 Replies)
Discussion started by: frustrated1
5 Replies
8. UNIX for Dummies Questions & Answers
I was trying to schedule a job to run on the last Sunday of October. To stop a process that I have running before daylight savings automatically falls back at 2AM then restart it after the hour has been regained. I thought I was smart (my mistake) and scheduled the 2 entries in cron. I figured that... (3 Replies)
Discussion started by: cindylouwho
3 Replies
9. Post Here to Contact Site Administrators and Moderators
Hey Neo - or other Unix.com staffers - I've selected my Timezone for the forums - however it's wrong for my Country - as we have Daylight Savings for 6 months of the year - so currently were 1 hour ahead of the time that is provided in the personal options pages. Can we add another for this - no... (5 Replies)
Discussion started by: peter.herlihy
5 Replies
TZSET(3) Linux Programmer's Manual TZSET(3)
NAME
tzset, tzname, timezone, daylight - initialize time conversion information
SYNOPSIS
#include <time.h>
void tzset (void);
extern char *tzname[2];
extern long timezone;
extern int daylight;
DESCRIPTION
The tzset() function initializes the tzname variable from the TZ environment variable. This function is automatically called by the other
time conversion functions that depend on the time zone. In a SysV-like environment it will also set the variables timezone (seconds West
of GMT) and daylight (0 if this time zone does not have any daylight savings time rules, nonzero if there is a time during the year when
daylight savings time applies).
If the TZ variable does not appear in the environment, the tzname variable is initialized with the best approximation of local wall clock
time, as specified by the tzfile(5)-format file localtime found in the system timezone directory (see below). (One also often sees
/etc/localtime used here, a symlink to the right file in the system timezone directory.)
If the TZ variable does appear in the environment but its value is NULL or its value cannot be interpreted using any of the formats speci-
fied below, Coordinated Universal Time (UTC) is used.
The value of TZ can be one of three formats. The first format is used when there is no daylight saving time in the local time zone:
std offset
The std string specifies the name of the time zone and must be three or more alphabetic characters. The offset string immediately follows
std and specifies the time value to be added to the local time to get Coordinated Universal Time (UTC). The offset is positive if the
local time zone is west of the Prime Meridian and negative if it is east. The hour must be between 0 and 24, and the minutes and seconds 0
and 59.
The second format is used when there is daylight saving time:
std offset dst [offset],start[/time],end[/time]
There are no spaces in the specification. The initial std and offset specify the standard time zone, as described above. The dst string
and offset specify the name and offset for the corresponding daylight savings time zone. If the offset is omitted, it defaults to one
hour ahead of standard time.
The start field specifies when daylight savings time goes into effect and the end field specifies when the change is made back to standard
time. These fields may have the following formats:
Jn This specifies the Julian day with n between 1 and 365. February 29 is never counted even in leap years.
n This specifies the Julian day with n between 1 and 365. February 29 is counted in leap years.
Mm.w.d This specifies day d (0 <= d <= 6) of week w (1 <= w <= 5) of month m (1 <= m <= 12). Week 1 is the first week in which day d
occurs and week 5 is the last week in which day d occurs. Day 0 is a Sunday.
The time fields specify when, in the local time currently in effect, the change to the other time occurs. If omitted, the default is
02:00:00.
The third format specifies that the time zone information should be read from a file:
:[filespec]
If the file specification filespec is omitted, the time zone information is read from the file localtime in the system timezone directory,
which nowadays usually is /usr/share/zoneinfo. This file is in tzfile(5) format. If filespec is given, it specifies another
tzfile(5)-format file to read the time zone information from. If filespec does not begin with a `/', the file specification is relative to
the system timezone directory.
FILES
The system time zone directory used depends on the (g)libc version. Libc4 and libc5 use /usr/lib/zoneinfo, and, since libc-5.4.6, when
this doesn't work, will try /usr/share/zoneinfo. Glibc2 will use the environment variable TZDIR, when that exists. Its default depends on
how it was installed, but normally is /usr/share/zoneinfo.
This timezone directory contains the files
localtime local time zone file
posixrules rules for POSIX-style TZ's
Often /etc/localtime is a symlink to the file localtime or to the correct time zone file in the system time zone directory.
CONFORMING TO
SVID 3, POSIX, BSD 4.3
NOTES
Note that the variable daylight does not indicate that daylight savings time applies right now. It used to give the number of some algo-
rithm (see the variable tz_dsttime in gettimeofday(2)). It has been obsolete for many years but is required by SUSv2.
BSD4.3 had a routine char *timezone(zone,dst) that returned the name of the time zone corresponding to its first argument (minutes West of
GMT). If the second argument was 0, the standard name was used, otherwise the daylight savings time version.
SEE ALSO
date(1), gettimeofday(2), time(2), ctime(3), getenv(3), tzfile(5)
2001-11-13 TZSET(3)