Calendar giving me the wrong hour and minute

Question

I am trying to get the time of a timestamp but I keep getting the wrong time when I use Calendar.HOUR and Calendar.MINUTE,no matter what the timestamp is it tells me the hour is 10 and the minute is 12.

now when I use the Calendar.getTime() it gives me the correct time so I dont understand? I just want to get the hour in 12hr format and the minute

here is how i go about doing it

public static String getRealTime(long time){

            Calendar cal = Calendar.getInstance();
    Log.d("Calendar",String.valueOf(time));
    cal.setTimeInMillis(time);
    Date timeS = cal.getTime();
    String sTime = timeS.toString(); // gives correct time in 24hr format
    int hr = cal.HOUR;               // gives me 10 no matter what the timestamp is
    int min = cal.MINUTE;            // gives me 12 no matter what the timestamp is
    String dMin = getDoubleDigit(min);
    int ampm = cal.AM_PM;
    String m = new String();
    if(ampm == 0){
        m = "AM";
    }else{
        m="PM";
    }
    String rtime = String.valueOf(hr)+":"+dMin+" "+m;
    return rtime;
}

so say the timestamp is 1316626200000 cal.getTime() gives me Wed Sep 21 13:30:00 EDT 2011 which would be the correct time but cal.HOUR gives me 10 for the hour which clearly is not what it should be. Why is it doing that?

score 13 · Accepted Answer · answered Sep 21 '11 at 04:21

cal.HOUR and cal.MINUTE are static final Integers for use in Calendar method calls. You would use this code to get the correct result:

   int hr = cal.get(Calendar.HOUR);
   int min = cal.get(Calendar.MINUTE);

Notice that I called the HOUR and MINUTE fields from Calendar and not your object cal. It is bad practice to call static members from an instantiated object.

score 2 · Answer 2 · edited May 23 '17 at 12:32

The great and almighty Android Reference page to the rescue!!! :D http://developer.android.com/reference/java/util/Calendar.html

So, here's the lowdown on why some of those things aren't returning the results you are expecting. First off, the Calendar.HOUR is not a reference to the current hour. First hint at that is the fact that it is in all caps, which by Java convention means that this is a constant (aka final) field. If you are developing in Eclipse it probably brought up a warning saying that you should probably reference the static variable with the class name Calendar instead of using the instance cal. Second hint: the reference page said so! ;)

Well, what should you do with the Calendar.HOUR then? That is a static constant so that you can use the cal.get() to find out. (see the reference page http://developer.android.com/reference/java/util/Calendar.html#get(int))

But! There is an easier way. The code that you might be looking for could be something like this:

public static String getRealTime(long time){
    return new SimpleDateFormat("HH:mm").format(new Date(time));
    //if you'd rather have the current time, just use new Date() without the time as a parameter
}

Another user has asked for a sorta similar things and there are a few other implementations on this page Display the current time and date in an Android application

Poo, I take too long to write my answers! :D – Bob Sep 21 '11 at 04:35 — Bob, Sep 21 '11 at 04:35

Calendar giving me the wrong hour and minute

2 Answers2