I need to use the CLI to see the time in arbitrary timezones. However, Debian doesn't respond to the recommended solution.
First, I set the local timezone.
dpkg-reconfigure tzdata
Then, I set the system time.
ntpdate pool.ntp.org
I update the hardware clock to reflect the system time.
hwclock --systohc --utc
Now, I follow this post:
http://www.linuxquestions.org/questions/programming-9/display-different-timezones-in-command-line-927660/
Which says that I can complete my task using a command such as this:
TZ=UTC date && TZ=CDT date && TZ=IST date
However, this is the output I get:
dpkg-reconfigure tzdata && ntpdate pool.ntp.org && hwclock --systohc --utc && TZ=UTC date && TZ=CDT date && TZ=IST date
Current default time zone: 'America/Chicago'
Local time is now: Tue Apr 16 14:45:29 CDT 2013.
Universal Time is now: Tue Apr 16 19:45:29 UTC 2013.
16 Apr 19:45:38 ntpdate[12036]: adjust time server 199.102.46.73 offset -0.036668 sec
Tue Apr 16 19:45:39 UTC 2013
Tue Apr 16 19:45:39 CDT 2013
Tue Apr 16 19:45:39 IST 2013
CDT and IST aren't valid timezone names, so date is defaulting to show you UTC time if you attempt to use those as your timezone.
I'm not sure which timezones you actually meant to use, but try a couple of these. They are valid timezone names.
TZ=Asia/Shanghai date
TZ=America/Vancouver date
TZ=Europe/London date
Related
We have a linux system that we are building with yocto.
We can read our hardware clock after reboots, change both system time and hardware time without any error (most of the time). However; after some new month, every year that we have tried we are running in to this error. "hwclock: RTC_RD_TIME: Invalid argument".
Example 1:
root#:~# date
Thu Apr 30 23:59:50 UTC 2020
root#:~# hwclock
Thu Apr 30 23:59:52 2020 0.000000 seconds
root#:~#
root#:~#
root#:~# date
Fri May 1 00:00:10 UTC 2020
root#:~# hwclock
hwclock: RTC_TD_TIME: Invalid argument
root#:~#
This is not happening every new month, if I do the same test in January linux can read the hwclock without any issues. It does also not matter if the unit is powered or not. If I set the hwclock to first of May 00:00:00 it can keep track of the time.
The same error occurs on the following month shift:
Feb (it does not matter if it is leap year or not) -> Mar
Apr -> May
Jun -> Jul
Sep -> Oct
Nov -> Dec
Dec (Not sure because of new year or new month) -> Jan
In my understanding, this is happening because rtc-lib.c cannot verify the time correctly.
I have tried on multiple different hardware
Does anyone have any idea what might cause this?
Solution:
The fault was not in rtc-lib.c. The cause of the error was a faulty RTC implementation. The RTC month value is 1-indexed, but the kernel assumes it is 0-indexed. Added a patch for this to rtc-[my_rtc_model].c and now it seems to be working.
I have problem with dynamically date change inside container. What I have:
docker run -it --privileged myDocker
the command above run container with privilege to change date
I can change date by:
date --set "12-12-12"
but after a few seconds, the date and time are setted the same as the host
root#660acd776c6b:/# date --set "12-12-12"
root#660acd776c6b:/# date
Wed Dec 12 00:00:01 UTC 2012
root#660acd776c6b:/# date
Wed Dec 12 00:00:02 UTC 2012
root#660acd776c6b:/# date
Wed Dec 12 00:00:02 UTC 2012
root#660acd776c6b:/# date
Tue Jan 15 10:14:26 UTC 2019
root#660acd776c6b:/# date
Tue Jan 15 10:14:27 UTC 2019
The container doesn't have installed ntp.
I can't use faketime because I use the date in .net application which doesn't use time from faketime. I can't change system clock using faketime.
How could I disable synchronization between container and host ?
Postgresql is rather good at handling timezones, using the classic tzdata database.
The server can convert past and future timestamps between the different timezones, following the rules in tzdata (offsets, dst changes, ..)
Is there a simple and efficient way, for a given timezone and a given date range, to extract all the timestamps within that range when a timezone modification event occured ?
the result should more or less contain the equivalent of the output of the zdump linux command.
zdump -v /usr/share/zoneinfo/America/Los_Angeles | grep 2017
Sun Mar 12 09:59:59 2017 UTC = Sun Mar 12 01:59:59 2017 PST isdst=0 gmtoff=-28800
Sun Mar 12 10:00:00 2017 UTC = Sun Mar 12 03:00:00 2017 PDT isdst=1 gmtoff=-25200
Sun Nov 5 08:59:59 2017 UTC = Sun Nov 5 01:59:59 2017 PDT isdst=1 gmtoff=-25200
Sun Nov 5 09:00:00 2017 UTC = Sun Nov 5 01:00:00 2017 PST isdst=0 gmtoff=-28800
select d::date
from (
select
d at time zone 'America/Los_Angeles' as la,
lead(d at time zone 'America/Los_Angeles') over (order by d) as la_,
d
from generate_series (
'2017-01-01'::timestamp,
'2017-12-31', '1 day'
) gs (d)
) s
where la::time <> la_::time;
d
------------
2017-03-12
2017-11-05
I'm trying to apply the timezone Europe/Berlin on a Raspberry PI running the Debian-based Raspbian.
sudo dpkg-reconfigure tzdata
returns
Current default time zone: 'Europe/Berlin'
Local time is now: Sun Jun 25 20:26:51 CEST 2017.
Universal Time is now: Sun Jun 25 18:26:51 UTC 2017.
but
sudo date
still returns the British Summer Time (BST) instead of the Europe/Berlin Central European Summer Time (CEST)
Sun Jun 25 19:26:55 BST 2017
If there is internet connection available follow the steps to set the
date/time:
sudo raspi-config
Internationalization options
Change Time Zone
Select geographical area
Select city or region.
Reboot your pi.
This way, you will have accurate time. Need not set the date again for every boot.
I don't know how to interpret this date format:
1394862706,
1394862645,
1400258321,
1400258250 etc. (each block is a different date)
Does someone understand in which format are them?
I believe they're Unix timestamps. For example, 1400258250 maps to 4:37:30 May 16 2014. They represent the number of seconds that have elapsed since the Unix epoch, January 1, 1970.
Here's a nice timestamp converter.
As others have noted, the 10-digit numbers are Unix timestamps, the number of seconds since 1970-01-01 00:00:00 +00:00, the Unix Epoch.
If you have GNU date, you can use the -d option (or --date) and the # prefix to analyze them (here, with TZ=US/Pacific or TZ=America/Los_Angeles):
$ for ts in 1394862706 1394862645 1400258321 1400258250; do date -d #$ts; done
Fri Mar 14 22:51:46 PDT 2014
Fri Mar 14 22:50:45 PDT 2014
Fri May 16 09:38:41 PDT 2014
Fri May 16 09:37:30 PDT 2014
$
If you add the -u or --utc option, then you get the output:
Sat Mar 15 05:51:46 UTC 2014
Sat Mar 15 05:50:45 UTC 2014
Fri May 16 16:38:41 UTC 2014
Fri May 16 16:37:30 UTC 2014