Solved

having trouble with time zones and daylight savings

Posted on 2011-03-19
18
340 Views
Last Modified: 2013-11-23
So i have this time in my DB
1300550400000
from what i read the display should no if to display daylight or not

when i run this code::
SmsEvents.getStart() returns 1300550400000


        TimeZone pTz = TimeZone.getTimeZone( "PST" );
        DateFormat pdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
        pdf.setTimeZone( pTz );
        Calendar dayp = Calendar.getInstance();
        dayp.setTimeZone( pTz );
        dayp.setTime( new Date((long)SmsEvents.getStart())  );
        System.out.println( pdf.format( dayp.getTime() ) );

        TimeZone mTz = TimeZone.getTimeZone( "MST" );
        DateFormat mdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
        mdf.setTimeZone( mTz );
        Calendar daym = Calendar.getInstance();
        daym.setTimeZone( mTz );
        daym.setTime( new Date((long)SmsEvents.getStart())  );
        System.out.println( mdf.format( daym.getTime() ) );

        TimeZone cTz = TimeZone.getTimeZone( "CST" );
        DateFormat cdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
        cdf.setTimeZone( cTz );
        Calendar dayc = Calendar.getInstance();
        dayc.setTimeZone( cTz );
        dayc.setTime( new Date((long)SmsEvents.getStart())  );
        System.out.println( cdf.format( dayc.getTime() ) );


i get the following results::
March 19, 2011 9:30:00 AM PDT
March 19, 2011 9:30:00 AM MST
March 19, 2011 11:30:00 AM CDT

why is mountain doing this. Am i doing something wrong?
I am confused







0
Comment
Question by:paries
  • 10
  • 6
  • 2
18 Comments
 
LVL 47

Expert Comment

by:for_yan
ID: 35172370
What is it that you don't like?
seems logical to me, I guess MST will give the same number as PDT
CDT is two hours difference with PDT
and I guess MDT will be one hour difference with PDT.
Isn't that what you'll expect?
0
 

Author Comment

by:paries
ID: 35172396
so my question is why is it
March 19, 2011 9:30:00 AM MST

should it have not been MDT??

0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172399


I got different output:


March 19, 2011 8:00:00 AM PST
March 19, 2011 9:00:00 AM MST
March 19, 2011 10:00:00 AM CST

Open in new window


I just modified your code a little bit (replacing SMSEvent):

     TimeZone pTz = TimeZone.getTimeZone( "PST" );
            DateFormat pdf = DateFormat.getDateTimeInstance( DateFormat.LONG, DateFormat.LONG );
            pdf.setTimeZone( pTz );
            Calendar dayp = Calendar.getInstance();
            dayp.setTimeZone( pTz );
            dayp.setTime( new Date((long)1300550400000L));
            System.out.println( pdf.format( dayp.getTime() ) );

            TimeZone mTz = TimeZone.getTimeZone( "MST" );
            DateFormat mdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
            mdf.setTimeZone( mTz );
            Calendar daym = Calendar.getInstance();
            daym.setTimeZone( mTz );
            daym.setTime( new Date((long)1300550400000L)  );
            System.out.println( mdf.format( daym.getTime() ) );

            TimeZone cTz = TimeZone.getTimeZone( "CST" );
            DateFormat cdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
            cdf.setTimeZone( cTz );
            Calendar dayc = Calendar.getInstance();
            dayc.setTimeZone( cTz );
            dayc.setTime( new Date((long)1300550400000L)  );
            System.out.println( cdf.format( dayc.getTime() ) );

Open in new window


0
PeopleSoft Has Never Been Easier

PeopleSoft Adoption Made Smooth & Simple!

On-The-Job Training Is made Intuitive & Easy With WalkMe's On-Screen Guidance Tool.  Claim Your Free WalkMe Account Now

 
LVL 47

Expert Comment

by:for_yan
ID: 35172417
When I changed all thre of them to
PDT, MDT nd CDT I got everything in GMT, like that:


March 19, 2011 4:00:00 PM GMT
March 19, 2011 4:00:00 PM GMT
March 19, 2011 4:00:00 PM GMT

Open in new window


Interesting, indeed
0
 

Author Comment

by:paries
ID: 35172434
i am running 1.5 i bet you you are running 1.6
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172442
I was just posting that I  have Java 1.5 (1.5.0_01)
(even more surprising).
Did you change to that same long number (just to have the codes identical).
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172449
I'm in Pacific zone, so my local time is 11:06 I guess it is PDT
0
 

Author Comment

by:paries
ID: 35172473
so i am using jdk1.5.0_15
wow this is so confusing....

I am at a loss
thats for you help.
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172478
It looks like my java does not understand PDT, CDT, MDT;
when I put "ABC" instaed - I also get GMT time in the result
0
 

Author Comment

by:paries
ID: 35172490
yeah that is the same with me.
but if i put in CST it realized i am in daylight savings and shows CDT
0
 

Author Comment

by:paries
ID: 35172509
wow, so i took this very simple jsp and moved to a 1.6.0_20 box

go the same results
March 19, 2011 11:25:22 AM PDT
March 19, 2011 11:25:22 AM MST
March 19, 2011 1:25:22 PM CDT



<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<%@ page import="java.text.SimpleDateFormat" %>
<%@ page import="java.util.*" %>
<%@ page import="java.text.DecimalFormat" %>
<%@ page import="java.text.DateFormat" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%
        Date now2 = new Date();

        TimeZone pTz = TimeZone.getTimeZone( "PST" );
        DateFormat pdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
        pdf.setTimeZone( pTz );
        Calendar dayp = Calendar.getInstance();
        dayp.setTimeZone( pTz );
        dayp.setTime( now2  ) ;
        System.out.println( pdf.format( dayp.getTime() ) );

        TimeZone mTz = TimeZone.getTimeZone( "MST" );
        DateFormat mdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
        mdf.setTimeZone( mTz );
        Calendar daym = Calendar.getInstance();
        daym.setTimeZone( mTz );
        daym.setTime( now2 );
        System.out.println( mdf.format( daym.getTime() ) );

        TimeZone cTz = TimeZone.getTimeZone( "CST" );
        DateFormat cdf = DateFormat.getDateTimeInstance( DateFormat.LONG,DateFormat.LONG );
        cdf.setTimeZone( cTz );
        Calendar dayc = Calendar.getInstance();
        dayc.setTimeZone( cTz );
        dayc.setTime( now2 );
        System.out.println( cdf.format( dayc.getTime() ) );

%>
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172511
I'll be in the office this afternoon; I have sveral java's there including 1.6 - I'll give it a try
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172516
All that looks really strange
0
 

Author Comment

by:paries
ID: 35172533
after some googling seems to be a common problem
if i do TimeZone mTz = TimeZone.getTimeZone( "America/Denver" );
it displays correctly
I think i am going to go that route
thanks for all your help

0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172591
And thanks for this interesting news also
0
 
LVL 86

Accepted Solution

by:
CEHJ earned 500 total points
ID: 35172614
Yes, 3 letter tzs are deprecated - use the longer city form
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35172753
If all stuff which is deprecated in Java would stop working today - we'll have a disaster much worse than any Japanese tsunami.
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 35172776
Well tzs are a little different than stuff like deprecated methods:

a. they are a moving target for Java
b. they're already either buggy or borderline buggy

For those reasons, it's worth running the tzupdater tool - it won't do you any harm and might do some good
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

By the end of 1980s, object oriented programming using languages like C++, Simula69 and ObjectPascal gained momentum. It looked like programmers finally found the perfect language. C++ successfully combined the object oriented principles of Simula w…
Are you developing a Java application and want to create Excel Spreadsheets? You have come to the right place, this article will describe how you can create Excel Spreadsheets from a Java Application. For the purposes of this article, I will be u…
Viewers learn how to read error messages and identify possible mistakes that could cause hours of frustration. Coding is as much about debugging your code as it is about writing it. Define Error Message: Line Numbers: Type of Error: Break Down…
Viewers will learn about basic arrays, how to declare them, and how to use them. Introduction and definition: Declare an array and cover the syntax of declaring them: Initialize every index in the created array: Example/Features of a basic arr…

726 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question