I want to create a TF-File for storing Unix Time Zone informations out of a TZ-String as define in POSIX 1003.1 section 8.3.
It seems that timezone compiler zic does not cover this.
For a test I created a file "MYZ.txt" compatible to "zic" dealing with a phantasie time zone "MYZ=My Zone" with UTC offset +0:30 (or +1:30 in summer):
#TZ=MYZ-0:30MYSZ,M3.5.0/2,M10.5.0/3
Rule MYsummer min max - Mar lastSun 2:00w 1:00 MYSZ
Rule MYsummer min max - Oct lastSun 3:00w 0 MYZ
Zone MYZ 0:30 MYsummer %s
The commented first line has the same information as the two rules and Zone information below.
zic MYZ.txt -d /tmp does what I want and stores the time zone information into "/tmp/MYZ".
What I like to use is something like calling
export TZ=MYZ-0:30MYSZ,M3.5.0/2,M10.5.0/3
zic -d /tmp
and having the same time zone information in "/tmp/MYZ" like above.
Of corse I could implement a tool creating "MYZ.txt" out of the TZ environment variable.
But I guess somthing similar is avaible within the UNIX/Linux standard tools.
This may be realted to TZ Variable, custom file .
Thanks for any help,
Tom
Related
So I am trying to alter the change timestamp on a file using a script I got from here: Setting/changing the ctime or "Change time" attribute on a file
#!/bin/sh
now=$(date)
echo $now
sudo date --set="qui nov 7 21:05:56 WET 2018"
chmod 777 $1
sudo date --set="$now"
This is the output:
qui nov 8 18:19:39 WET 2018
date: invalid date ‘qui nov 7 21:05:56 WET 2018’
date: invalid date ‘qui nov 8 18:19:39 WET 2018’
What is the matter? The output from date is not a valid date? I tried the fix suggested in the comment to the answer I linked, but it also doesn't work.
AFAIK The reason why the arguments are different:
$ info date
Invoking 'date' with no FORMAT argument is equivalent to invoking it
with a default format that depends on the 'LC_TIME' locale category.
While under Setting the time:
If given an argument that does not start with '+', 'date' sets the
system clock to the date and time specified by that argument (as
described below). You must have appropriate privileges to set the
system clock. Note for changes to persist across a reboot, the hardware
clock may need to be updated from the system clock, which might not
happen automatically on your system.
The argument must consist entirely of digits, which have the
following meaning:
'MM'
month
'DD'
day within month
'hh'
hour
'mm'
minute
'CC'
first two digits of year (optional)
'YY'
last two digits of year (optional)
'ss'
second (optional)
Note, the '--date' and '--set' options may not be used with an
argument in the above format. The '--universal' option may be used with
such an argument to indicate that the specified date and time are
relative to Coordinated Universal Time rather than to the local time
zone.
how to get local date & time in linux terminal while server configured in UTC or different timezone?
here is what I get now but I'd like to see in local timezone. For eg: PST/PDT.
[jenkins#myServer ~]$ date
Thu Jul 28 18:16:48 UTC 2016
I'm not looking to change system time using hwclock or updating /etc/localtime. Just want to change it for a user.
Also, please let me know - how to persist it for future logins.
Use the TZ environment variable to pass the desired timezone to date:
TZ=<timezone> date
You can find the available timezones in the /usr/share/zoneinfo/ directory and subdirectories. For example, /usr/share/zoneinfo/America/New_York defines TZ=America/New_York.
Example:
$ date
Fri Jul 29 06:31:53 BDT 2016
$ TZ='America/New_York' date
Thu Jul 28 20:31:58 EDT 2016
$ TZ='America/Los_Angeles' date
Thu Jul 28 17:31:54 PDT 2016
For a local time, use "date". For UTC time, use "date -u". Note that, if you use "date" in the server's terminal it returns the server local time.
You can show local time by overriding the TZ environment variable for the process which prints the date. POSIX says a lot about the topic, beginning with
This variable shall represent timezone information. The contents of the environment variable named TZ shall be used by the ctime(), ctime_r(), localtime(), localtime_r() strftime(), mktime(), functions, and by various utilities, to override the default timezone.
Conventional 3-character timezone values were some time ago (more or less) standardized to deprecate the 3-character forms, using the combined standard and daylight savings time form. The preferred form used for PDT is PST8PDT.
There's a page on VMware showing the names and mentioning that they are used on Linux; you may notice that very few of those are 3-character form (aside from the generic UTC+offset).
Further reading:
Valid timeZone Values (VMware):
IANA - Time Zone Database
I'm trying to use $date -u to get UTC time zone. It works fine but how can i set GTM to get a different time zone. For example, how can i complete that command to check GMT+5 or GMT+6 time zone in command line in Linux?
Any idea how can i do it?
You can set the timezone just for the one call to the date command (without changing the timezone that your system is set to) like so:
TZ=Asia/Calcutta date
Note the space before the date command.
Maybe this is the wrong way, but try setting the time zone, then calling date, then unsetting the time zone.
export TZ=Asia/Calcutta
date
unset TZ
There's a small list here of the time zones: Link To Wikipedia.
I have a string of the format
20110724T080000Z
and I want to convert that to local time in a shell script on linux. I thought I simply could give it as input to date, but I don't seem to be able to tell date what format my input date has.
this
date -d "20110724T080000Z" -u
would make date complain
date: invalid date `20110724T080000Z'
Also, what is the format of the form "20110724T080000Z" called? I have had little success trying to google for it.
That's ISO8601 "basic format" for a combined date and time. date does not seem to be able to parse 20110724T080000Z, but if you are prepared to do a few string substitutions it parses 20110724 08:00:00Z correctly.
The date program recognizes yyyy-mm-ddTHH:MM:SS (as well as yyyy-mm-dd HH:MM:SS), so:
a=20110724T080000Z
b=${a:0:4}-${a:4:2}-${a:6:5}:${a:11:2}:${a:13:2}
date +%F_%T -d "${b} +0"
Would print 2011-07-24_12:30:00 in my locale.
its called Zulu time. Its the same as UCT, which used to be referred to as GMT. It's used with the military to specify UCT so there is no confusion on correspondance.
http://en.wikipedia.org/wiki/Date_(Unix)
this command should work according to wikipedia:
date [-u|--utc|--universal] [mmddHHMM[[cc]yy][[.SS]] The only valid option for this form specifies Coordinated Universal Time.
You might try taking advantage of perl:
perl -e 'print scalar localtime(shift), "\n"' 20110724T080000Z
Though u might have to tweak this a little to get it to work correctly. Ok, I don't know exactly why the perl version doesn't do it well, but here is a Ruby version I've tried, though I can't pick the time out well:
ruby -e "require 'date';print Date.strptime('20110724T080000Z','%Y%m%dT%H%M%SZ').ctime"
gives:
Sun Jul 24 00:00:00 2011
From where does the date command in Linux get the timezone information?
I cannot see /etc/localtime file and /usr/share/zoneinfo directory in my system. Still when i execute the date command i get the following output
Thu Dec 9 16:28:18 UTC 2010
Kindly tell me from where does the command get the timezone information?
Thanks,
LinuxPenseur
Don't forget that UTC is how standard Unix systems store the date/time in the real time clock. You have to jump through hoops using funny programs (see the hwclock(8) manpage) if you dual-boot to Windows, which prefers the local time to be stored in the CMOS real time clock.
So the date(1) program is simply showing you the results of "I have no configured time zone":
# date -u
Thu Dec 9 10:40:54 UTC 2010
# TZ=UTC date
Thu Dec 9 10:40:57 UTC 2010
# TZ=PST8PDT date
Thu Dec 9 02:41:02 PST 2010
#
From http://www.wikihow.com/Change-the-Timezone-in-Linux
On mobile phones and other small devices that run Linux, the time zone
is stored differently. It is written in /etc/TZ, in the format that is
described, for instance, in [4] . Edit this file manually or use
echo (for instance, echo GMT0BST > /etc/TZ to set the the timezone of
the United Kingdom).
From http://www.radisys.com/files/support_downloads/03245-02_MPCMM0001_MPCMM0002_CMM_Software_TPS.pdf
The CMM determines the offset to local timezone maintained in file
/etc/cmm/TZ and automatically updates the time.
This should help :
http://www.hypexr.org/linux_date_time_help.php