Develop Reference

How to format Joda Time to dd-mm-yyyy in android?

String DOB = new DateTime(Long.parseLong(dob) * 1000, DateTimeZone.UTC ).toString();
// Current
// YYYY-MM-DD
// DOB = "1994-05-10T00:00.000Z"
// Required
// DD-MM-YYYY
// DOB = "10-05-1994"
I want to remove the hh:mm:ss and format the date using Joda-Time DateTimeFormatter.

try this:
DateTimeFormatter dtf = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSS zzz");
// pass your DOB String
DateTime jodatime = dtf.parseDateTime(DOB);
// Format for output
DateTimeFormatter dtfOut = DateTimeFormat.forPattern("dd-MM-yyyy");
// Print the date
System.out.println(dtfOut.print(jodatime));

tl;dr
Use java.time classes.
Instant.ofEpochSecond( 1_485_748_890L )
.atZone( ZoneId.of( "America/Montreal" ) )
.toLocalDate()
.format(
DateTimeFormatter.ofPattern ( "dd-MM-uuuu" )
.withLocale ( Locale.UK )
)
29-01-2017
Joda-Time
If you want a date-only value without a time-of-day, you should be using the org.joda.time.LocalDate class.
FYI, the Joda-Time project is now in maintenance mode, with the team advising migration to the java.time classes. Much of java.time is back-ported to Java 6, Java 7, and Android (see below).
java.time
The LocalDate class represents a date-only value without time-of-day and without time zone.
LocalDate birthdate = LocalDate.of( 1994 , 5 , 10 );
If your input is a count of whole seconds since the epoch of first moment of 1970 in UTC (1970-01-01T00:00:00Z), convert to an Instant. The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).
Instant instant = Instant.ofEpochSecond( 1_485_748_890L );
To view this moment through the lens of a particular region’s wall-clock time, assign a time zone (ZoneId) to get a ZonedDateTime.
A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = instant.atZone( z );
The LocalDate class represents a date-only value without time-of-day and without time zone.
LocalDate ld = zdt.toLocalDate();
To generate a String representing the value of your object, call toString for a string in standard ISO 8601 format, YYYY-MM-DD.
ld.toString(): 2017-01-29
For other formats, use the DateTimeFormatter class. You can specify a formatting pattern, or let the class automatically localize.
DateTimeFormatter f = DateTimeFormatter.ofPattern ( "dd-MM-uuuu" ).withLocale ( Locale.UK );
String output = ld.format ( f );
instant.toString(): 2017-01-30T04:01:30Z
zdt.toString(): 2017-01-29T23:01:30-05:00[America/Montreal]
ld.toString(): 2017-01-29
output: 29-01-2017
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8 and SE 9 and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
See How to use ThreeTenABP….

try this :
String textDate ="1994-05-10T00:00.000Z"; //Date to convert
DateTimeFormatter DATE_FORMAT = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ssZ"); //Default format
SimpleDateFormat SIMPLE_DATE_FORMAT = new SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()); //Needed format
DateTime dateTime = new DateTime(DATE_FORMAT.parseDateTime(textDate), DateTimeZone.forID(current.getID()));
Calendar cal=dateTime.toCalendar(Locale.getDefault());
String formatted = SIMPLE_DATE_FORMAT.format(cal.getTime()); //Final Required date

Calendar set DAY_OF_WEEK not correct

Hi i have some problem with DAY_OF_WEEK. After research but don't know why.
Input date is :
30/01/2016 - SATURDAY
After run :
calendar.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);
Output :
31/01/2016 - SUNDAY(Wrong).
I want it must 30/01/2016 - SATURDAY,
Please help me ?

try by passing Date
Calendar calendar = Calendar.getInstance;
calendar.set(2016, Calendar.JANUARY, 30);
or try this too
Calendar c = Calendar.getInstance();
c.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);
for(int i=0; i<7; i++)
{
System.out.print("Start Date : " + c.getTime() + ", ");
c.add(Calendar.DAY_OF_WEEK, 6);
}

tl;dr
LocalDate.of( 2016 , Month.JANUARY , 30 )
.with( TemporalAdjusters.next( DayOfWeek.SATURDAY ) )
2016-02-06
java.time
The modern approach uses java.time classes rather than the troublesome old Calendar class that is now legacy.
LocalDate
The LocalDate class represents a date-only value without time-of-day and without time zone.
A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
If no time zone is specified, the JVM implicitly applies its current default time zone. That default may change at any moment, so your results may vary. Better to specify your desired/expected time zone explicitly as an argument.
Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" ) ;
LocalDate today = LocalDate.now( z ) ;
If you want to use the JVM’s current default time zone, ask for it and pass as an argument. If omitted, the JVM’s current default is applied implicitly. Better to be explicit, as the default may be changed at any moment during runtime by any code in any thread of any app within the JVM.
ZoneId z = ZoneId.systemDefault() ; // Get JVM’s current default time zone.
Or specify a date. You may set the month by a number, with sane numbering 1-12 for January-December.
LocalDate ld = LocalDate.of( 1986 , 2 , 23 ) ; // Years use sane direct numbering (1986 means year 1986). Months use sane numbering, 1-12 for January-December.
Or, better, use the Month enum objects pre-defined, one for each month of the year. Tip: Use these Month objects throughout your codebase rather than a mere integer number to make your code more self-documenting, ensure valid values, and provide type-safety.
LocalDate ld = LocalDate.of( 1986 , Month.FEBRUARY , 23 ) ;
Adjuster
To move from one date to another, use a TemporalAdjuster implementation found in TemporalAdjusters class. Specify the desired day-of-week using [DayOfWeek][2] enum.
LocalDate previousOrSameMonday = today.with( TemporalAdjusters.previousOrSame( DayOfWeek.SATURDAY ) ) ;
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….

Days of the week on Android

I'm working on an Android app where I need to display the days of the week from the calendar. Can I do that using the calendar API ? or there is a library that can I use ?
Thanks

For date handling in Android, I recommend 310ABP, a port of the Java 8 new date APIs for Android.

Use Calendar object to get these things done.

You could use the JodaTime library to display the current day of the week.
LocalDate newDate = new LocalDate();
int dayOfWeek = newDate.getDayOfWeek();

or there is a library that can I use ?
Yes. Use the back-port of the java.time classes. See "Android" item below.
Using java.time
LocalDate
The LocalDate class represents a date-only value without time-of-day and without time zone.
A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" );
LocalDate today = LocalDate.now( z );
TemporalAdjuster
To get the first day of the week, (a) decide what is the first day of the week for you, (b) use a TemporalAdjuster implementation defined in TemporalAdjusters to get the date for a specific [DayOfWeek][6] enum object.
LocalDate ld = today.with( TemporalAdjusters.previousOrSame( DayOfWeek.MONDAY ) ) ;
To get a week’s worth of dates, add a day at a time.
LocalDate localDate = ld ; // Initialize our looping variable.
List<LocalDate> dates = new ArrayList<>( 7 ) ;
for( int i = 0 , i < 7 , i ++ ) { // Loop seven times, to cover a week.
localDate = localDate.plusDays( i );
dates.add( localDate ) ;
}
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
See How to use ThreeTenABP….

Calendar Time Not setting up

I am trying to set the calendar hour and minute by using the following code
Calendar c=Calendar.getInstance();
c.set(Calendar.HOUR,4);
c.set(Calendar.MINUTE, 23);
but it is always displaying 11 as hour and 12 as minute.

tl;dr
ZonedDateTime.of( // Represent a moment on the timeline adjusted into a particular time zone.
LocalDate.now( ZoneId.of( "Pacific/Auckland" ) ) , // Capture the current date for a particular time zone.
LocalTime.of( 4 , 23 ) , // Hard-code the time-of-day value desired. Will be adjusted as needed to handle anomalies such as DST.
ZoneId.of( "Pacific/Auckland" ) // Apply a particular time zone to this date-time.
)
java.time
You are using troublesome old date-time classes that are now legacy, supplanted by the java.time classes.
You seem to want the current date with a specific time-of-day.
You ignore the crucial issue of time zone.A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
If no time zone is specified, the JVM implicitly applies its current default time zone. That default may change at any moment, so your results may vary. Better to specify your desired/expected time zone explicitly as an argument.
Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" ) ;
If you want to use the JVM’s current default time zone, ask for it and pass as an argument. If omitted, the JVM’s current default is applied implicitly. Better to be explicit.
ZoneId z = ZoneId.systemDefault() ; // Get JVM’s current default time zone.
Determine today’s current date for a particular time zone.
LocalDate today = LocalDate.now( z ) ;
Represent your target time-of-day.
LocalTime lt = LocalTime.of( 4 , 23 ) ;
Combine with zone to get a ZonedDateTime. If your time-of-day is not valid for that date in that zone because of anomalies such as Daylight Saving Time (DST), the class automatically adjusts the time.
ZonedDateTime zdt = ZonedDateTime.of( today , lt , z ) ;
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….

How to get localization of day in week

I couldnt find a symbol for that in SimpleDateFormat
How can I get the current day's localized name?
For example: Monday: 1. day of week ; Tuesday: 2.day, wednesday:3.day .....
I want to get Presentation Number "1" instead of Monday ...

As per other questions, you don't need SimpleDateFormat to get the numeric day of the week - that is provided by Calendar directly via the DAY_OF_WEEK field (which goes from 1 to 7 where 1 is SUNDAY and 7 is SATURDAY):
Calendar today = Calendar.getInstance();
int dayOfWeek = today.get(Calendar.DAY_OF_WEEK);
// Day of Week is a number between 1 and 7 where 1 is Sunday.
int dayOfWeekMondayFirst = (dayOfWeek + 5) % 7 + 1;

tl;dr
For the number 1-7, meaning Monday-Sunday, for today:
LocalDate.now().getDayOfWeek().getValue()
For the localized name of the day of the week:
LocalDate // Represent a date-only, without time-of-day and without time zone.
.now( // Get today’s current date as seen in the wall-clock time used by the people of a particular region (a time zone).
ZoneId.of( "Africa/Tunis" ) // Specify time zone.
) // Returns a `LocalDate`.
.getDayOfWeek() // Returns one of seven `DayOfWeek` enum objects.
.getDisplayName( // Localize the name of the day-of-week.
TextStyle.FULL , // How long or abbreviated should the localized string be.
Locale.UK // Specify a `Locale` to determine the human language and cultural norms to use in localizing.
) // Returns a string.
Monday
java.time
The modern approach uses the java.time classes that long ago supplanted the terrible legacy date-time classes such as SimpleDateFormat.
To get the day-of-week today, we need the date.
LocalDate
The LocalDate class represents a date-only value without time-of-day and without time zone or offset-from-UTC.
A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
If no time zone is specified, the JVM implicitly applies its current default time zone. That default may change at any moment during runtime(!), so your results may vary. Better to specify your desired/expected time zone explicitly as an argument.
Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 2-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" ) ;
LocalDate today = LocalDate.now( z ) ;
If you want to use the JVM’s current default time zone, ask for it and pass as an argument. If omitted, the JVM’s current default is applied implicitly. Better to be explicit, as the default may be changed at any moment during runtime by any code in any thread of any app within the JVM.
ZoneId z = ZoneId.systemDefault() ; // Get JVM’s current default time zone.
DayOfWeek
The DayOfWeek enum pre-defines a set of seven objects, one for each day of the week.
Ask the LocalDate object for its DayOfWeek.
DayOfWeek dow = ld.getDayOfWeek() ;
Ask the DayOfWeek object to automatically localize its name. The DayOfWeek::getDisplayName method translates the name of the day into any human language specified by a Locale such as Locale.US or Locale.CANADA_FRENCH.
String output = dow.getDisplayName( TextStyle.FULL , Locale.CANADA_FRENCH );
lundi
Or, in US English.
String output = dow.getDisplayName( TextStyle.FULL , Locale.US );
Monday
To get the number of the day-of-week, where Monday-Sunday is 1-7 per the ISO 8601 standard, ask the DayOfWeek enum object for its value.
int dowNumber = dow.getValue() ; // 1-7 for Monday-Sunday.
To get the number 1-7 as part of a larger formatting pattern use e or c as directed in the DateTimeFormatter class.
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.