Conversion from 12 hours time to 24 hours time in java

Question

In my app, I have a requirement to format 12 hours time to 24 hours time. What is the method I have to use?

For example, time like 10

Answer 1

Try this to calculate time difference between two times.

first it will convert 12 hours time into 24 hours then it will take diff between two times

String a = "09/06/18 01:55:33 AM";
            String b = "07/06/18 05:45:33 PM";
            String [] b2 = b.split(" ");
            String [] a2 = a.split(" ");
            SimpleDateFormat displayFormat = new SimpleDateFormat("HH:mm:ss");
            SimpleDateFormat parseFormat = new SimpleDateFormat("hh:mm:ss a");
            String time1 = null ;
            String time2 = null ;
            if ( a.contains("PM") && b.contains("AM")) {
                 
                 Date date = parseFormat.parse(a2[1]+" PM");
                 time1 = displayFormat.format(date);
                 time2 = b2[1];
            }else if (b.contains("PM") && a.contains("AM")) {
                Date date = parseFormat.parse(a2[1]+" PM");
                time1 = a2[1];
                time2 = displayFormat.format(date);
            }else if (a.contains("PM") && b.contains("PM")){
                Date datea = parseFormat.parse(a2[1]+" PM");
                Date dateb = parseFormat.parse(b2[1]+" PM");
                time1 = displayFormat.format(datea);
                time2 = displayFormat.format(dateb);
            }   
            System.out.println(time1);
            System.out.println(time2);      
            SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
            Date date1 = format.parse(time1);
            Date date2 = format.parse(time2);
            long difference = date2.getTime() - date1.getTime(); 
            System.out.println(difference);
            System.out.println("Duration: "+DurationFormatUtils.formatDuration(difference, "HH:mm"));

For More Details Click Here