Develop Reference

How do I change the display of date of birth in java?

In my Java code, date of birth is retrieved from a database in the format 1999-04-30. How can I out.println this in a different format? Like this: 30/04/1999

You can format date as follows,
SimpleDateFormat format = new SimpleDateFormat();
String DateToStr = format.format(yourDataBaseDate);
format = new SimpleDateFormat("dd/MM/yyyy");
DateToStr = format.format(yourDataBaseDate);
System.out.println(DateToStr);
This is sample date format for your
question.

Hopefully, the date is retrieved as a java.sql.Date, which does not have a specific form.
To format such a date value, use:
java.sql.Date birthdate = resultSet.getDate("Birthdate");
SimpleDateFormat dateFmt = new SimpleDateFormat("dd/MM/yyyy");
String text = dateFmt.format(birthdate);
Or, in java.time (Java 8 and later):
java.time.LocalDate birthdate = resultSet.getDate("Birthdate").toLocalDate();
DateTimeFormatter dateFmt = DateTimeFormatter.ofPattern("dd/MM/uuuu");
String text = birthdate.format(dateFmt);

convert str time to kml timeStamp in java

i building a kml file and there is a line of timestamp:
<gx:TimeStamp>
<when>2002-07-09T19:00:00-08:00</when>
</gx:TimeStamp>
i need convert time like: "1430477311" to "2002-07-09T19:00:00-08:00" format
how ?
(java code)
tnx a lot

You are wanting to convert from your timeformat to XML Date Format (ISO-8601) -
long timeStamp = 1430477311L;
java.util.Date yourDate = new java.util.Date(timeStamp*1000); //ms
SimpleDateFormat yyyyMMddTHHmmssSDF = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");
String date = yyyyMMddTHHmmssSDF.format(yourDate);
Simple Date Format reference.

Simply pass the timestamp to a Date type:
Timestamp stamp = new Timestamp(inputTimestamp);
Date date = new Date(stamp.getTime());
//change the to the format that you need
DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
String timeStr = df.format(date);

How to format my date with SimpleDateFormat?

I'm trying to set a date format, but when i run this code
String oldstring = "2013-01-1";
System.out.println("oldstring = "+oldstring);
Date date = new SimpleDateFormat("yyyy-mm-dd").parse(oldstring);
System.out.println("datefield = "+date);
i take result:
oldstring = 2013-01-1
datefield = Tue Jan 01 00:01:00 MSK 2013
Why datefield isn't equal 2013-01-1?

At first mm in yyyy-mm-dd mean minute not Month. to set month use MM.
It would be look like this :
Date date = new SimpleDateFormat("yyyy-MM-dd").parse(oldstring);
UPDATE
Try this:
String oldstring = "2013-01-1";
System.out.println("oldstring = "+oldstring);
Date date = new SimpleDateFormat("yyyy-mm-dd").parse(oldstring);
String sdf = new SimpleDateFormat("yyyy-mm-dd").format(date);
System.out.println("datefield = "+sdf);
If you don't use new SimpleDateFormat("yyyy-mm-dd").format(date);
you getting standard date format which include all info. If you want special format you need to use
new SimpleDateFormat("yyyy-mm-dd").format(date);
Also read this article about date formatting

The type of datefield is Date, so the toString method will basically always return the same format, as you are not overriding it.
So what you need to do, is basically:
String oldstring = "2013-01-1";
System.out.println("oldstring = "+oldstring);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf.parse(oldstring);
System.out.println("datefield = "+date);
String outDateStr = sdf.format(date);
System.out.println("newstring = "+outDateStr);

Use MM for month. mm is for minutes

Extract time from date String

How can I format the "2010-07-14 09:00:02" date string to depict just "9:00"?

Use DateTimeFormatter to convert between a date string and a real LocalDateTime object. with a LocalDateTime as starting point, you can easily apply formatting based on various patterns as definied in the javadoc of the DateTimeFormatter.
String originalString = "2010-07-14 09:00:02";
LocalDateTime dateTime = LocalDateTime.parse(originalString, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
String newString = DateTimeFormatter.ofPattern("H:mm").format(dateTime); // 9:00
In case you're not on Java 8 or newer yet, use SimpleDateFormat to convert between a date string and a real Date object. with a Date as starting point, you can easily apply formatting based on various patterns as definied in the javadoc of the SimpleDateFormat.
String originalString = "2010-07-14 09:00:02";
Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(originalString);
String newString = new SimpleDateFormat("H:mm").format(date); // 9:00

Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse("2010-07-14 09:00:02");
String time = new SimpleDateFormat("H:mm").format(date);
http://download.oracle.com/javase/1.4.2/docs/api/java/text/SimpleDateFormat.html

A very simple way is to use Formatter (see date time conversions) or more directly String.format as in
String.format("%tR", new Date())

The other answers were good answers when the question was asked. Time moves on, Date and SimpleDateFormat get replaced by newer and better classes and go out of use. In 2017, use the classes in the java.time package:
String timeString = LocalDateTime.parse(dateString, DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss"))
.format(DateTimeFormatter.ofPattern("H:mm"));
The result is the desired, 9:00.

I'm assuming your first string is an actual Date object, please correct me if I'm wrong. If so, use the SimpleDateFormat object: http://download.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html. The format string "h:mm" should take care of it.

If you have date in integers, you could use like here:
Date date = new Date();
date.setYear(2010);
date.setMonth(07);
date.setDate(14)
date.setHours(9);
date.setMinutes(0);
date.setSeconds(0);
String time = new SimpleDateFormat("HH:mm:ss").format(date);

let datestring = "2017-02-14 02:16:28"
let formatter = DateFormatter()
formatter.dateStyle = DateFormatter.Style.full
formatter.timeStyle = DateFormatter.Style.full
formatter.dateFormat = "yyyy-MM-dd hh:mm:ss"
let date = formatter.date(from: datestring)
let date2 = formatter.String(from: date)

Blackberry Java String to date conversion

I used following code to convert string to date but it is applying timezone of device while conversion.
I don't need this but I want same date/time from that string like
String = "2009-07-31 07:59:17.427"
Date = 2009-07-31 07:59:17.427
Date formatter = new Date(HttpDateParser.parse("2009-07-31 07:59:17.427"));
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
String strCustomDateTime = dateFormat.format(formatter);

You may take in account default timezone offset to date you get after parsing:
public static String StringToDate(String dateToParse) {
Date formatter = new Date(HttpDateParser.parse(dateToParse));
SimpleDateFormat dateFormat = new SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss.SSS");
int offset = TimeZone.getDefault().getRawOffset();
formatter.setTime(formatter.getTime() + offset);
String strCustomDateTime = dateFormat.format(formatter);
return strCustomDateTime;
}

What is the problem, exactly? You are trying to convert "2009-07-31 07:59:17.427" into a point in time, but, this does not specify a unique point in time -- without a timezone. So you do need a timezone, and the library is necessary picking one, the platform's current timezone.
If the problem is you wish to specify a different time zone, then call DateFormat.setTimeZone():
format.setTimeZone(TimeZone.getTimeZone("your time zone"));