TZ, localtime and strftime problem on AIX and Solaris Post: 302805515

Sponsored Content

Top Forums Programming TZ, localtime and strftime problem on AIX and Solaris Post 302805515 by biju64 on Friday 10th of May 2013 09:37:41 AM

05-10-2013

Registered User

Thank you both.
That seems to be the problem - mystery solved - and both were correct !

Under OLSON format the TZ depends on the data in /usr/share/lib/zoneinfo and under POSIX format we specify the DST details directly and so it does not depend on anything else.

Using zdump -vc to dump the zoneinfo database shows that there are gaps in the data stored w.r.t. DST for different years.
Specifically in the cases where the above code does not work the data for 1970 is missing.

We have another AIX machine where Europe/London was available but details for 1970 is missing and so the code gives the wrong output:

zdump -vc 1970 Europe/London
<snip>
Europe/London Sun Oct 29 02:00:00 1967 UTC = Sun Oct 29 02:00:00 1967 GMT isdst=0
Europe/London Sun Feb 18 01:59:59 1968 UTC = Sun Feb 18 01:59:59 1968 GMT isdst=0
Europe/London Sun Feb 18 02:00:00 1968 UTC = Sun Feb 18 03:00:00 1968 BST isdst=1
Europe/London Sat Oct 26 22:59:59 1968 UTC = Sat Oct 26 23:59:59 1968 BST isdst=1
Europe/London Sat Oct 26 23:00:00 1968 UTC = Sun Oct 27 00:00:00 1968 BST isdst=0
Europe/London Mon Jan 18 03:14:07 2038 UTC = Mon Jan 18 03:14:07 2038 GMT isdst=0
Europe/London Tue Jan 19 03:14:07 2038 UTC = Tue Jan 19 03:14:07 2038 GMT isdst=0
<snip>

And where the data is available (and correct), the code gives the right output.

So the moral of the story is :
1) Using Posix format is reliable and to be preferred
2) If using Olson format check the zoneinfo database using zdump and if the data for the year is there and correct all is well. Otherwise first ensure that the zoneinfo database is corrected.

biju64

View Public Profile for biju64

Find all posts by biju64

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Perl + localtime()

ok here is a perl date question not asked befor. i know i am feeling small for not knowing. BUT!!!! $ENV{TZ}="US/Central"; ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=localtime(); how can i do the addition to year so i can get the current year w/o going $ntime=$year+1900;...

2. UNIX for Advanced & Expert Users

converting localtime to unixtime

hi, how to convert the localtime to unixtime? i have date from the date command in unix i want to convert it into unixtime thnx

3. Solaris

AIX & Solaris 10 problem

I have this command in my script and it's working fine with AIX: ls init?*.ora 2>/dev/null | egrep -i -e "" the same command is failing in Solaris 10. does anyone have better idea how to make it work for both ? Thanks

4. Shell Programming and Scripting

gawk and strftime()

Strange behaviour of the strftime() function from gawk (3.1.5): $ awk 'BEGIN{print strftime("%T", 3600)}' > 02:00:00 $ awk 'BEGIN{print strftime("%T", 0)}' > 01:00:00 Obviously something with DST but I can not figure out why? To me 3600 epoch seconds remains 01:00, DST or not. From...

5. Shell Programming and Scripting

PERL localtime Warning

Hello All, I am facing a warning "Argument "" isn't numeric in localtime at" what i m using is below my $timestamp = Timestamp(time); go_log("###############$timestamp###############"); can some one please suggest the way to avoid this message :confused:

6. Shell Programming and Scripting

date with perl localtime

Hi Experts, I know how to handle normal date changes in perl. Most of my requirement are full filled with following: $date1 = strftime "%Y%m%d",localtime; $date2 = strftime "%Y%m%d",localtime(time -24 * 60 * 60); $date3 = strftime "%Y%m%d",localtime(time +24 * 60 * 60); $date4 = strftime...

7. Programming

strftime equivalent in c++

HI, i wish to convert a millsec value to a readable string format. the one option is to use strftime. However this is a bit costly (1-5 micros). is there a a faster way to do so with just string manipulation (Note i have the date object which has the time details but wish o avoid strftime)

8. Shell Programming and Scripting

Perl help LocalTime in New Format

Hi, I'm new to perl scripting and am trying it out. I have a file written in the following format: myfile-MMDDYY where MM is the number of the Month; DD the Day and YY the last two of the year... (Apologies for dumbing this down; I'm trying to be clear). There is a new file put onto my...

9. Shell Programming and Scripting

How to use a variable in perl localtime()?

Hi all, a=$1 ## b=`echo "86400 * $a"|bc` `perl -e 'use POSIX qw(strftime);$now_string = strftime "%d/%m/%Y", localtime(time-$b); print $now_string,"\n";' > date_file` but im always getting current date; can any one suggest me any the improvement the above works fine if i use some thing...

10. Shell Programming and Scripting

Help on awk strftime

cat file 41285.000034722223 41285.000567129631 41285.000069444446 41285.001122685186 41285.000092592592 41285.001620370371 41285.000138888892 41285.00340277778 41285.000185185185 41285.000405092593 41285.000196759262 41285.000856481478 41285.000208333331 41285.000717592593...

LEARN ABOUT PHP

datetime.gettimezone

DATETIME.GETTIMEZONE(3) 						 1						   DATETIME.GETTIMEZONE(3)

DateTime::getTimezone - Return time zone relative to given DateTime

       Object oriented style

SYNOPSIS

       public DateTimeZone DateTime::getTimezone (void	)

DESCRIPTION

       DateTimeZone DateTimeImmutable::getTimezone (void  ) DateTimeZone DateTimeInterface::getTimezone (void  )

       Procedural style
       DateTimeZone date_timezone_get (DateTimeInterface  $object)

	Return time zone relative to given DateTime.

PARAMETERS

	      o $object
		-Procedural style only: A DateTime object returned by date_create(3)

RETURN VALUES

	Returns a DateTimeZone object on success or FALSE on failure.

EXAMPLES

       Example #1

	      DateTime.getTimezone(3) example

	      Object oriented style

	      <?php
	      $date = new DateTime(null, new DateTimeZone('Europe/London'));
	      $tz = $date->getTimezone();
	      echo $tz->getName();
	      ?>

	      Procedural style

	      <?php
	      $date = date_create(null, timezone_open('Europe/London'));
	      $tz = date_timezone_get($date);
	      echo timezone_name_get($tz);
	      ?>

	      The above examples will output:

	      Europe/London

SEE ALSO 
DateTime.setTimezone(3).
PHP Documentation Group 												   DATETIME.GETTIMEZONE(3)

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Perl + localtime()

Discussion started by: Optimus_P

2. UNIX for Advanced & Expert Users

converting localtime to unixtime

Discussion started by: AshishK

3. Solaris

AIX & Solaris 10 problem

Discussion started by: talashil

4. Shell Programming and Scripting

gawk and strftime()

Discussion started by: ripat