Time Conversion from 12-hour to 24-hour clock in Java

Question

I have a time in a string in the following format.

"MM/dd/yyyy hh:mm AM/PM"

I need to get the time in 24:00 hours format

ex:

String str = "04/30/2013 10:20PM"

I need to get the time as 22:20

Answer 1

You have to use SimpleDateFormat to any kind of date-time conversion.
You can try this:

import java.text.SimpleDateFormat;
import java.util.Date;

public class DateConversion {
   public void convertDate() {
      try{
       SimpleDateFormat df = new SimpleDateFormat("HH:mm");
       SimpleDateFormat pf = new SimpleDateFormat("MM/dd/yyyy hh:mm a");
       Date date = pf.parse("10:20PM");
       System.out.println(pf.format(date) + " = " + df.format(date));
        }catch(Exception e){
        // Do your exception handling over here.
        }
   }
}

This will solve your problem I guess.
This will give an output : 22:20

Please let me know in case of any issue.

Answer 2

Use SimpleDateFormat to convert a string to a Date object and then format it.

String str = "04/30/2013 10:20PM";
Date date = new SimpleDateFormat("MM/dd/yyyy hh:mma").parse(str);
String result = new SimpleDateFormat("HH:mm").format(date);

See here for a similar question.

Answer 3

Use "HH" instead of "hh" For example:

Date dNow = new Date( );
SimpleDateFormat ft =   new SimpleDateFormat ("MM/dd/yyyy HH:mm ");
System.out.println("Current Date: " + ft.format(dNow));

in this link, specially in "Simple DateFormat format codes:" you can find that :

Character   Description               Example

h           Hour in A.M./P.M. (1~12)    12
H           Hour in day (0~23)          22