Develop Reference

json to human readable date date shows one less than actual date

I convert json date to human readable date but it shows less one then actual date. I
used this code to convert it:
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
Calendar calendar = Calendar.getInstance();
Long timeInMillis = Long.valueOf(AttendanceModelList.get(position).getEmpdate());
calendar.setTimeInMillis(timeInMillis);
Date date=new Date(timeInMillis);
viewHolder.textemployeedate.setText(df.format(date));
Please help

You say as summary:
Your calendar date is one day less than expected when you try to
interprete a global timestamp of type java.util.Date as calendar
date.
This phenomenon can happen due to timezone effects or midnight change. Before viewing the technical solution, you have to ask yourself:
What is your default (system) timezone using TimeZone.getDefault()?
Do you run your code on a server which has not the expected timezone?
In which timezone do you wish to view the calendar date? (the timezone associated with your expected "actual" date)
How to specify the timezone?
java.util.Date d = ...; // from your JSON-timeInMillis?
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String tz = "Asia/Kolkata"; // or any other valid tz id
sdf.setTimeZone(TimeZone.getTimeZone(tz));
System.out.println(sdf.format(d));

Date in android is returning future date instead of current date

I am facing problem where I am extracting date from Date class in android and using it in my activity, But my problem here is everything works fine but date function returns 25/03/2014 instead of current date.
Now I am confused why it is returning this irrelavent date instead of current date, Also there is no error.
My code:
import java.util.date;
SimpleDateFormat dateformat=new SimpleDateFormat("dd/mm/yyyy");
dateformat.format(new Date());
Please help to know how to get current date.

From SimpleDateFormat API reference,
d day in month
m minute in hour
M month in year
y year
Change dd/mm/yyyy to dd/MM/yyyy for day/month/year format.

Please check Time & Date settings of your emulator, sometimes that causes the issues like those as well.

Use this dude
Date date = new Date(location.getTime());
DateFormat dateFormat = android.text.format.DateFormat.getDateFormat(getApplicationContext());
System.out.println("Time: " + dateFormat.format(date));

This is giving me correct time
String ntime = new SimpleDateFormat("hh:mm:ss").format(new Date());

For Date u can use
String ndate = new SimpleDateFormat("yyyy-MM-dd").format(new Date());

Calculate with date in Android

Does anyone here know what the best way is to calculate the date 2 days in the past?
I've got this piece of code to retrieve the current date:
public static String getDateTime (String Format){
SimpleDateFormat sdf = new SimpleDateFormat(Format);
return sdf.format(new Date());
}
But I want to be able to calculate the date 2 days in the past. So decrease the date with 2 days. Anyone who knows what the best way is to do this?
Thanks in advance

Using Calendar is probably the easiest way. Assuming that you have defined Format as per the question:
// get Now
Calendar cal = Calendar.getInstance();
// go back two days
cal.add(Calendar.DAY_OF_YEAR, -2);
// display
SimpleDateFormat sdf = new SimpleDateFormat(Format);
String string = sdf.format(cal.getTime());

Just use Calendar's add() function:
Calendar c = Calendar.getInstance();
c.setTime(yourDateObject);
c.add(Calendar.DAY_OF_MONTH, -2);
It will automatically change the month, year, etc. if necessary.

Calendar not returning GMT

I am trying to get a calendar object set to GMT, but the getTime() always returns the time in GMT+1 (my current time). I have tried:
Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("UTC"));
Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("skeniver"));
They all apparently return GMT, because
cal.getTimeZone().getDisplayName()
returns "GMT+00:00"; but
cal.getTime().toString();
always displays the time in GMT+1.
Does anyone have any idea why this is happening?

You need to adjust for daylight savings. I'm not sure if this will help but it's code I use for adjusting any timezone to UTC in an app that's currently being used by a number of people around the world. I use Date instead of Calendar but it works...
Date dateTimeNow = new Date();
TimeZone tz = TimeZone.getDefault();
int currentOffsetFromUTC = tz.getRawOffset() + (tz.inDaylightTime(dateTimeNow) ? tz.getDSTSavings() : 0);
Date dateTimeNowUTC = new Date(dateTimeNow.getTime() - currentOffsetFromUTC);

If you want to in string then prefer the DateFormat or SimpleDateFormat for this
here is example
SimpleDateFormat sdf = new SimpleDateFormat(); // here you can also define your format of date for e.g. "dd/MM/yyyy z"
sdf.setTimeZone("GMT");
Calendar cal = Calendar.getInstance();
System.out.println(sdf.format(cal.getTime()));

Calendar.getTime() returns a Date object. In Java, a Date is just a holder to a long timestamp starting in the UNIX epoch.
To display a Date in a different TimeZone than the default, you can use a SimpleDateFormat.

how to add no days to date object not calendar object

I have a Date object. Now I want to add days to that Date object.
So how that can be done? Actually using Calendar object that can be done I know.
But in my case, I haven't used a calendar objects. Instead only used date object.
For Example, suppose I have a date object
Date dtStartDate=o.getStartDate();
int x=28;
Now what I want to do is to add 28 to this date object, means if the dtStartDate is 1 July 2011
then after adding 28, dtStartDate will be 29 July 2011.
Please suggest it to me.
Thanks in advance

You can add Day using below
Calendar c1 = Calendar.getInstance();
c1.add(Calendar.DAY_OF_MONTH, 1);
Here 1 is number of Day you can add.
OR
Date dtStartDate=o.getStartDate();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");
Calendar c = Calendar.getInstance();
c.setTime(dtStartDate);
c.add(Calendar.DATE, 3); // number of days to add
String dt = sdf.format(c.getTime()); // dt is now the new date
Toast.makeText(this, "" + dt, 5000).show();
May be your problem solved.

You could add the equivilent number of milliseconds to the time retrieved from Date, e.g.:
long millis = dtStartDate.getTime();
millis = millis + x*24*60*60*1000;
Date dtEndDate = new Date();
dtEndDate.setTime(millis);

You can easily do this in two simple ways my friend. First one is:
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DAY_OF_MONTH, 1);
and the second one is:
Calendar cal = Calendar.getInstance();
cal.add(Calendar.HOUR_OF_DAY, 24);
I think you would like to find this thing. Though there are so many persons are there who choose the first method.
Thanks.