Solved

Calendar.HOUR_OF_DAY shows wrong timing

Posted on 2010-09-23
17
1,429 Views
Last Modified: 2012-05-10
I am trying to do some time calculation using the Calendar.HOUR_OF_DAY but it always gives the output as 11 . I tried to change the timezone in my PC to different time zone and still no difference . Where does this Java function look for the current time ? will it look in the machine in whicjh we are running the program for the current time?
0
Comment
Question by:FranklinRaj22
  • 5
  • 4
  • 3
  • +3
17 Comments
 
LVL 51

Expert Comment

by:Huseyin KAHRAMAN
ID: 33748041
you should use getInstance first

Calendar rightNow = Calendar.getInstance();
then use rightNow.HOUR_OF_DAY

I guess ;)
0
 

Author Comment

by:FranklinRaj22
ID: 33748270
i assign a gregorian calendar instance before tryin to pull the hour of the day information.

Calendar calendar = new GregorianCalendar();
0
 
LVL 51

Expert Comment

by:Huseyin KAHRAMAN
ID: 33748400
then use

Calendar calendar = new GregorianCalendar();
alert(calendar.HOUR_OF_DAY);

not

Calendar.HOUR_OF_DAY
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 14

Accepted Solution

by:
CPColin earned 500 total points
ID: 33748445
Calendar.HOUR_OF_DAY is the constant you pass to Calendar.get() to get the right value. You want something like:

calendar.get(Calendar.HOUR_OF_DAY);
0
 
LVL 51

Expert Comment

by:Huseyin KAHRAMAN
ID: 33748573
0
 
LVL 51

Expert Comment

by:Huseyin KAHRAMAN
ID: 33748591
0
 
LVL 51

Expert Comment

by:Huseyin KAHRAMAN
ID: 33748596
sample
// create a GregorianCalendar with the Pacific Daylight time zone
 // and the current date and time
 Calendar calendar = new GregorianCalendar(pdt);
 Date trialTime = new Date();
 calendar.setTime(trialTime);

 // print out a bunch of interesting things
 System.out.println("ERA: " + calendar.get(Calendar.ERA));
 System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
 System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
 System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
 System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));

Open in new window

0
 
LVL 92

Expert Comment

by:objects
ID: 33750201
you can set the timezonme using the setTimezone() method
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 33752447
>>I am trying to do some time calculation using the Calendar.HOUR_OF_DAY but it always gives the output as 11

Please post your code
0
 

Author Comment

by:FranklinRaj22
ID: 33756883
Piece of my code : Please advice.

public void run()
    {
       Thread t = Thread.currentThread();
        String name = t.getName();
        System.out.println("entered loop() - " + name);
        Calendar calendar = new GregorianCalendar();        
//int hour = Calendar.get(calendar.HOUR_OF_DAY);
        while(calendar.HOUR_OF_DAY < 20){  
         S.O.P("time is not 8 PM yet")
        }
   }
0
 

Author Comment

by:FranklinRaj22
ID: 33756917
Thanks Guys , I did this and it wrked ....

while(calendar.get(Calendar.HOUR_OF_DAY) < 20){
0
 
LVL 92

Expert Comment

by:objects
ID: 33757934
that should actually be:

public void run()
{
       Thread t = Thread.currentThread();
        String name = t.getName();
        System.out.println("entered loop() - " + name);
        while(Calendar.getInstance().get(Calendar.HOUR_OF_DAY) < 20){  
            S.O.P("time is not 8 PM yet")
        }
   }
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 33758075
You'll be eating a lot of CPU cycles like that. Use a timer with a 1 second cycle and a callback if required
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 33758094
>>You'll be eating a lot of CPU cycles like that.

(and unnecessary allocations)
0
 

Author Comment

by:FranklinRaj22
ID: 33939690
let me use call back and see ..
0
 
LVL 27

Expert Comment

by:mrcoffee365
ID: 37419067
This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone 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

For beginner Java programmers or at least those new to the Eclipse IDE, the following tutorial will show some (four) ways in which you can import your Java projects to your Eclipse workbench. Introduction While learning Java can be done with…
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…
Viewers will learn about the different types of variables in Java and how to declare them. Decide the type of variable desired: Put the keyword corresponding to the type of variable in front of the variable name: Use the equal sign to assign a v…
This theoretical tutorial explains exceptions, reasons for exceptions, different categories of exception and exception hierarchy.

713 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