Question

Friends,I am trying to calculate the difference between two date&time entries that the user is providing me. The logic I am using is the code snippet shared below. Please correct me where I am going wrong and do help with solution also.

 private void CalculateDifference(String arrDate, String arrTime,
                String deptDate, String deptTime) {

            String arrival=arrDate+" "+arrTime;
            String dept=deptDate+" "+deptTime;
            System.out.println("Inside calculate diff");
            System.out.println("ARRIVAL IS"+arrival);
            System.out.println("DEPARTURE IS"+dept);
            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm");
            Date date1 = null;
            Date date2 = null;
            try {
                date1 = format.parse(arrival);
                date2 = format.parse(dept);
                System.out.println("ARRIVAL IN TRY IS"+date1);
                System.out.println("DEPARTURE IN TRY IS"+date2);
                long difference = date2.getTime() - date1.getTime(); 
                System.out.println("Time Difference is"+difference);
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }


        }

LOG-CAT

09-20 11:38:57.569: I/System.out(20028): Inside calculate diff
09-20 11:38:57.569: I/System.out(20028): ARRIVAL IS30-April  - 2012 11:38
09-20 11:38:57.569: I/System.out(20028): DEPARTURE IS20-Sept  - 2012 11:38
09-20 11:38:57.569: W/System.err(20028): java.text.ParseException: Unparseable date: "30-April  - 2012 11:38"
09-20 11:38:57.569: W/System.err(20028):    at java.text.DateFormat.parse(DateFormat.java:626)
09-20 11:38:57.569: W/System.err(20028):    at com.travel.tracker.Add.CalculateDifference(Add.java:84)
09-20 11:38:57.569: W/System.err(20028):    at com.travel.tracker.Add.onClick(Add.java:66)
09-20 11:38:57.569: W/System.err(20028):    at android.view.View.performClick(View.java:2485)
09-20 11:38:57.579: W/System.err(20028):    at android.view.View$PerformClick.run(View.java:9080)
09-20 11:38:57.579: W/System.err(20028):    at android.os.Handler.handleCallback(Handler.java:587)
09-20 11:38:57.579: W/System.err(20028):    at android.os.Handler.dispatchMessage(Handler.java:92)
09-20 11:38:57.579: W/System.err(20028):    at android.os.Looper.loop(Looper.java:130)
09-20 11:38:57.579: W/System.err(20028):    at android.app.ActivityThread.main(ActivityThread.java:3687)
09-20 11:38:57.579: W/System.err(20028):    at java.lang.reflect.Method.invokeNative(Native Method)
09-20 11:38:57.579: W/System.err(20028):    at java.lang.reflect.Method.invoke(Method.java:507)
09-20 11:38:57.579: W/System.err(20028):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
09-20 11:38:57.579: W/System.err(20028):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
09-20 11:38:57.579: W/System.err(20028):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

For SimpleDateFormat to work you need formatter string and string you pass in the same format ie. in your case yyyy-MM-dd HH:mm

So 30-April - 2012 11:38 should be 2012-04-30 11:38

From DateFormat Java doc which is parent class of SimpleDateFormat you can specify month in following format.

Sept is still not a valid month name in any format.

M -> 9
MM -> 09
MMM -> Sep
MMMM -> September