Develop Reference

How to fetch recent seven days from specific date

If the date is 2017-03-30 that i want to fetch the date from 2017-03-23 to 2017-03-30
I try to use this code let my String change to Date format
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date dateParse = sdf.parse("2017-03-30");
then i'm stuck , cause i take the reference is get the current time like this
Calendar c = Calendar.getInstance();
c.add(Calendar.DATE, -7);
//may be my dateParse should put here , but i don't know how to do
Date monday = c.getTime();//it get the current time
String preMonday = sdf.format(monday);
Is any one can teach me how to fetch these seven days ? Thanks in advance.

You can use the code below
SimpleDateFormatdateFormat = new SimpleDateFormat("dd MMM yyyy");
Calendar c = Calendar.getInstance();
String date = dateFormat.format(c.getTime());
c.add(Calendar.DATE, 7);
String date1 = dateFormat.format(c.getTime());

Parse the date:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date myDate = sdf.parse("2017-03-30");
First Solution 1) And then either figure out how many milliseconds you need to subtract:
Date newDate = new Date(myDate.getTime() - 604800000L); // 7 * 24 * 60 * 60 * 1000
Second Solution 2) Or use the API provided by the java.util.Calendar class:
Calendar calendar = Calendar.getInstance();
calendar.setTime(myDate);
calendar.add(Calendar.DAY_OF_YEAR, -7);
Date newDate = calendar.getTime();
Then, if you need to, convert it back to a String:
String date = dateFormat.format(newDate);
This answer is from here
EDIT:
If you need output as 2017-03-29 2017-03-28 2017-03-27 ...... 2017-03-23 then try below code
for(int i = 1; i <= 7; i++){
Calendar calendar = Calendar.getInstance();
calendar.setTime(myDate);
calendar.add(Calendar.DAY_OF_YEAR, -i);
Date newDate = calendar.getTime();
String date = dateFormat.format(newDate);
//here in date you can get all date from and output as 2017-03-29 2017-03-28 2017-03-27 ...... 2017-03-23
}
Hope you need this

convert millisecond to Joda Date Time or for zone 0000

please tell me how to convert milliseconds to joda Date time??
formatter = DateTimeFormat.forPattern("dd/MM/yyyy'T'HH:mm:ss").withZone(DateTimeZone.forOffsetHoursMinutes(00, 00));
even tried
String millisecond="14235453511"
DateTime.parse(millisecond);

The answer given by #Adam S is almost okay. However, I would prefer to specify the timezone explicitly. Without specifying it you get the constructed DateTime-instance in the system timezone. But you want the zone "0000" (UTC)? Then look for this alternative constructor:
String milliseconds = "14235453511";
DateTime someDate = new DateTime(Long.valueOf(milliseconds), DateTimeZone.UTC);
System.out.println(someDate); // 1970-06-14T18:17:33.511Z

There's a constructor that takes milliseconds:
long milliseconds = 14235453511;
DateTime someDate = new DateTime(milliseconds);

You can use this
Calendar calendar = new GregorianCalendar();
DateFormat formatter = new SimpleDateFormat("dd MMM yyyy HH:mm:ss z");
formatter.setCalendar(calendar);
String timeZone = "GMT+2:00";
formatter.setTimeZone(TimeZone.getTimeZone(timeZone));
String time = formatter.format(calendar.getTime());
System.out.println(time);
I hope this will help you

Change timestamp into another gmt+ timestamp

Here goes my code but getting the same timestamp after changing the timezone.
TimeZone timeZone = TimeZone.getTimeZone("GMT+11");
Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();
cal1.setTimeInMillis(Long.parseLong(classListDto.get(i)
.getClassStartTime()) * THOUSAND);
cal2.setTimeInMillis(Long.parseLong(classListDto.get(i)
.getClassEndTime()) * THOUSAND);
cal1.setTimeZone(timeZone);
cal2.setTimeZone(timeZone);
long startTimestamp = cal1.getTimeInMillis();
long endTimestamp = cal2.getTimeInMillis();

Try something like this, instead of setting the timezone in your Calendar instance.
TimeZone timeZone = TimeZone.getTimeZone("GMT+11");
Calendar cal1 = Calendar.getInstance();
cal1.setTimeInMillis(Long.parseLong(classListDto.get(i).getClassStartTime()) * THOUSAND);
Date tempDate = cal1.getTime();
SimpleDateFormat df = new SimpleDateFormat();
SimpleDateFormat df1 = new SimpleDateFormat();
df.setTimeZone(timeZone);
Date gmtDate = df1.parse(df.format(tempDate)); // Put this in a Try/Catch block
long startTimestamp = gmtDate.getTime();
Hope this helps! I know its crappy to use 2 SimpleDateFormat objects though.

You can see the timezone change in your code if you do a cal1.getField(Calendar.HOUR); instead of just reading the milliseconds. Calendar seems to store the millis only in terms of UTC: http://docs.oracle.com/javase/1.5.0/docs/api/java/util/Calendar.html#getTimeInMillis()

How to get the day, year, hours, min Individually from date format "yyyy-MM-dd'T'HH:mm:ss.SSSZ"?

I am doing a programme that stores the present time and date in "yyyy-MM-dd'T'HH:mm:ss.SSSZ" this format. and I am storing it in database as a string. when i am collecting the data i need the individual values like day, year, min, seconds etc.. how can i do this?
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
String now = formatter.format(new Date());
Thank you,

Just use parse instead of format :
String dateFromDB = "";
SimpleDateFormat parser = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
Date yourDate = parser.parse(dateFromDB);
And then you can can read any field you want using java.util.Date & Calendar API :
Calendar calendar = Calendar.getInstance();
calendar.setTime(yourDate);
calendar.get(Calendar.DAY_OF_MONTH); //Day of the month :)
calendar.get(Calendar.SECOND); //number of seconds
//and so on
I hope it fits your needs

I'm suggesting that you store times in the DB as "timeInMillis". In my experience it simplifies code and it allows you to compare times values to eachother.
To store a time:
Calendar calendar = Calendar.getInstance(); // current time
long timeInMillis = calendar.getTimeInMillis();
mDb.saveTime (timeInMillis); // adjust this to work with your DB
To retrieve a time:
long timeInMillis = mDb.getTime();
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis (timeInMillis);
int milliSeconds = calendar.get(MILLISECOND);
//etc

There are these methods available to get the individual parts of a date
getDate()
getMinutes()
getHours()
getSeconds()
getMonth()
getTime()
getTimezoneOffset()
getYear()

Try using : int hour = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
Here,
Calendar.HOUR_OF_DAY gives you the 24-hour time.
Calendar.HOUR gives you the 12-hour time.

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.