topic Is DST in effect? in Operating System - HP-UX

Is DST in effect?

Craig Sterley — Sun, 09 Mar 2008 12:53:13 GMT

How can i determine via a script is Daylight Savings Time is in effect or not?

Re: Is DST in effect?

James R. Ferguson — Sun, 09 Mar 2008 13:21:47 GMT

Hi Craig:

# perl -le '$dst=(localtime)[8];print $dst==1 ? "in DST":"not in DST"'

...is an easy way to answer your question.

Regards!

...JRF...

Re: Is DST in effect?

Craig Sterley — Sun, 09 Mar 2008 13:51:59 GMT

Thank you for the quick response. That did the trick.

Re: Is DST in effect?

Craig Sterley — Sun, 09 Mar 2008 13:54:59 GMT

case closed. Thanks again

Re: Is DST in effect?

Matti_Kurkela — Sun, 09 Mar 2008 14:03:06 GMT

A shell script solution: examine the timezone identifier (available with "date +%Z").

For example, at the US West Coast, it should return PST when using Standard Time and PDT when the Daylight Saving Time is in effect.

This can be made timezone-agnostic by using the fact that the only thing we need to know is whether the current timezone identifier is at the beginning of the TZ value, or at the end.

Disclaimer: quick&dirty, with very little testing. If it breaks, you can keep the pieces.

#!/bin/sh
NOW=$(date +%Z)
if [ ${TZ#$NOW} != ${TZ} ]
then
echo "Standard time"
elif [ ${TZ%$NOW} != ${TZ} ]
then
echo "Daylight time"
else
echo "ERROR: date command outputted a timezone identifier not listed in TZ"
fi

MK