DateFormat

public abstract class DateFormat
extends Format

java.lang.Object
   ↳ java.text.Format
     ↳ java.text.DateFormat


DateFormat is an abstract class for date/time formatting subclasses which formats and parses dates or time in a language-independent manner. The date/time formatting subclass, such as SimpleDateFormat, allows for formatting (i.e., date → text), parsing (text → date), and normalization. The date is represented as a Date object or as the milliseconds since January 1, 1970, 00:00:00 GMT.

DateFormat provides many class methods for obtaining default date/time formatters based on the default or a given locale and a number of formatting styles. The formatting styles include FULL, LONG, MEDIUM, and SHORT. More detail and examples of using these styles are provided in the method descriptions.

DateFormat helps you to format and parse dates for any locale. Your code can be completely independent of the locale conventions for months, days of the week, or even the calendar format: lunar vs. solar.

To format a date for the current Locale, use one of the static factory methods:

myString = DateFormat.getDateInstance().format(myDate);
 

If you are formatting multiple dates, it is more efficient to get the format and use it multiple times so that the system doesn't have to fetch the information about the local language and country conventions multiple times.

DateFormat df = DateFormat.getDateInstance();
 for (int i = 0; i < myDate.length; ++i) {
     output.println(df.format(myDate[i]) + "; ");
 }
 

To format a date for a different Locale, specify it in the call to getDateInstance().

DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE);
 

You can use a DateFormat to parse also.

myDate = df.parse(myString);
 

Use getDateInstance to get the normal date format for that country. There are other static factory methods available. Use getTimeInstance to get the time format for that country. Use getDateTimeInstance to get a date and time format. You can pass in different options to these factory methods to control the length of the result; from SHORT to MEDIUM to LONG to FULL. The exact result depends on the locale, but generally:

  • SHORT is completely numeric, such as 12.13.52 or 3:30pm
  • MEDIUM is longer, such as Jan 12, 1952
  • LONG is longer, such as January 12, 1952 or 3:30:32pm
  • FULL is pretty completely specified, such as Tuesday, April 12, 1952 AD or 3:30:42pm PST.

You can also set the time zone on the format if you wish. If you want even more control over the format or parsing, (or want to give your users more control), you can try casting the DateFormat you get from the factory methods to a SimpleDateFormat. This will work for the majority of countries; just remember to put it in a try block in case you encounter an unusual one.

You can also use forms of the parse and format methods with ParsePosition and FieldPosition to allow you to

  • progressively parse through pieces of a string.
  • align any particular field, or find out where it is for selection on the screen.

Synchronization

Date formats are not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.

Summary

Nested classes

class DateFormat.Field

Defines constants that are used as attribute keys in the AttributedCharacterIterator returned from DateFormat.formatToCharacterIterator and as field identifiers in FieldPosition

Constants

int AM_PM_FIELD

Useful constant for AM_PM field alignment.

int DATE_FIELD

Useful constant for DATE field alignment.

int DAY_OF_WEEK_FIELD

Useful constant for DAY_OF_WEEK field alignment.

int DAY_OF_WEEK_IN_MONTH_FIELD

Useful constant for DAY_OF_WEEK_IN_MONTH field alignment.

int DAY_OF_YEAR_FIELD

Useful constant for DAY_OF_YEAR field alignment.

int DEFAULT

Constant for default style pattern.

int ERA_FIELD

Useful constant for ERA field alignment.

int FULL

Constant for full style pattern.

int HOUR0_FIELD

Useful constant for zero-based HOUR field alignment.

int HOUR1_FIELD

Useful constant for one-based HOUR field alignment.

int HOUR_OF_DAY0_FIELD

Useful constant for zero-based HOUR_OF_DAY field alignment.

int HOUR_OF_DAY1_FIELD

Useful constant for one-based HOUR_OF_DAY field alignment.

int LONG

Constant for long style pattern.

int MEDIUM

Constant for medium style pattern.

int MILLISECOND_FIELD

Useful constant for MILLISECOND field alignment.

int MINUTE_FIELD

Useful constant for MINUTE field alignment.

int MONTH_FIELD

Useful constant for MONTH field alignment.

int SECOND_FIELD

Useful constant for SECOND field alignment.

int SHORT

Constant for short style pattern.

int TIMEZONE_FIELD

Useful constant for TIMEZONE field alignment.

int WEEK_OF_MONTH_FIELD

Useful constant for WEEK_OF_MONTH field alignment.

int WEEK_OF_YEAR_FIELD

Useful constant for WEEK_OF_YEAR field alignment.

int YEAR_FIELD

Useful constant for YEAR field alignment.

Fields

protected Calendar calendar

The Calendar instance used for calculating the date-time fields and the instant of time.

protected NumberFormat numberFormat

The number formatter that DateFormat uses to format numbers in dates and times.

Protected constructors

DateFormat()

Create a new date format.

Public methods

Object clone()

Overrides Cloneable

boolean equals(Object obj)

Overrides equals

final StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition fieldPosition)

Formats the given Object into a date-time string.

abstract StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition)

Formats a Date into a date-time string.

final String format(Date date)

Formats a Date into a date-time string.

static Locale[] getAvailableLocales()

Returns an array of all locales for which the get*Instance methods of this class can return localized instances.

Calendar getCalendar()

Gets the calendar associated with this date/time formatter.

static final DateFormat getDateInstance(int style, Locale aLocale)

Gets the date formatter with the given formatting style for the given locale.

static final DateFormat getDateInstance(int style)

Gets the date formatter with the given formatting style for the default FORMAT locale.

static final DateFormat getDateInstance()

Gets the date formatter with the default formatting style for the default FORMAT locale.

static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle)

Gets the date/time formatter with the given date and time formatting styles for the default FORMAT locale.

static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)

Gets the date/time formatter with the given formatting styles for the given locale.

static final DateFormat getDateTimeInstance()

Gets the date/time formatter with the default formatting style for the default FORMAT locale.

static final DateFormat getInstance()

Get a default date/time formatter that uses the SHORT style for both the date and the time.

NumberFormat getNumberFormat()

Gets the number formatter which this date/time formatter uses to format and parse a time.

static final DateFormat getTimeInstance(int style)

Gets the time formatter with the given formatting style for the default FORMAT locale.

static final DateFormat getTimeInstance(int style, Locale aLocale)

Gets the time formatter with the given formatting style for the given locale.

static final DateFormat getTimeInstance()

Gets the time formatter with the default formatting style for the default FORMAT locale.

TimeZone getTimeZone()

Gets the time zone.

int hashCode()

Overrides hashCode

boolean isLenient()

Tell whether date/time parsing is to be lenient.

Date parse(String source)

Parses text from the beginning of the given string to produce a date.

abstract Date parse(String source, ParsePosition pos)

Parse a date/time string according to the given parse position.

Object parseObject(String source, ParsePosition pos)

Parses text from a string to produce a Date.

void setCalendar(Calendar newCalendar)

Set the calendar to be used by this date format.

void setLenient(boolean lenient)

Specify whether or not date/time parsing is to be lenient.

void setNumberFormat(NumberFormat newNumberFormat)

Allows you to set the number formatter.

void setTimeZone(TimeZone zone)

Sets the time zone for the calendar of this DateFormat object.

Inherited methods

Constants

AM_PM_FIELD

Added in API level 1
public static final int AM_PM_FIELD

Useful constant for AM_PM field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 14 (0x0000000e)

DATE_FIELD

Added in API level 1
public static final int DATE_FIELD

Useful constant for DATE field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 3 (0x00000003)

DAY_OF_WEEK_FIELD

Added in API level 1
public static final int DAY_OF_WEEK_FIELD

Useful constant for DAY_OF_WEEK field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 9 (0x00000009)

DAY_OF_WEEK_IN_MONTH_FIELD

Added in API level 1
public static final int DAY_OF_WEEK_IN_MONTH_FIELD

Useful constant for DAY_OF_WEEK_IN_MONTH field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 11 (0x0000000b)

DAY_OF_YEAR_FIELD

Added in API level 1
public static final int DAY_OF_YEAR_FIELD

Useful constant for DAY_OF_YEAR field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 10 (0x0000000a)

DEFAULT

Added in API level 1
public static final int DEFAULT

Constant for default style pattern. Its value is MEDIUM.

Constant Value: 2 (0x00000002)

ERA_FIELD

Added in API level 1
public static final int ERA_FIELD

Useful constant for ERA field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 0 (0x00000000)

FULL

Added in API level 1
public static final int FULL

Constant for full style pattern.

Constant Value: 0 (0x00000000)

HOUR0_FIELD

Added in API level 1
public static final int HOUR0_FIELD

Useful constant for zero-based HOUR field alignment. Used in FieldPosition of date/time formatting. HOUR0_FIELD is used for the zero-based 12-hour clock. For example, 11:30 PM + 1 hour results in 00:30 AM.

Constant Value: 16 (0x00000010)

HOUR1_FIELD

Added in API level 1
public static final int HOUR1_FIELD

Useful constant for one-based HOUR field alignment. Used in FieldPosition of date/time formatting. HOUR1_FIELD is used for the one-based 12-hour clock. For example, 11:30 PM + 1 hour results in 12:30 AM.

Constant Value: 15 (0x0000000f)

HOUR_OF_DAY0_FIELD

Added in API level 1
public static final int HOUR_OF_DAY0_FIELD

Useful constant for zero-based HOUR_OF_DAY field alignment. Used in FieldPosition of date/time formatting. HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock. For example, 23:59 + 01:00 results in 00:59.

Constant Value: 5 (0x00000005)

HOUR_OF_DAY1_FIELD

Added in API level 1
public static final int HOUR_OF_DAY1_FIELD

Useful constant for one-based HOUR_OF_DAY field alignment. Used in FieldPosition of date/time formatting. HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock. For example, 23:59 + 01:00 results in 24:59.

Constant Value: 4 (0x00000004)

LONG

Added in API level 1
public static final int LONG

Constant for long style pattern.

Constant Value: 1 (0x00000001)

MEDIUM

Added in API level 1
public static final int MEDIUM

Constant for medium style pattern.

Constant Value: 2 (0x00000002)

MILLISECOND_FIELD

Added in API level 1
public static final int MILLISECOND_FIELD

Useful constant for MILLISECOND field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 8 (0x00000008)

MINUTE_FIELD

Added in API level 1
public static final int MINUTE_FIELD

Useful constant for MINUTE field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 6 (0x00000006)

MONTH_FIELD

Added in API level 1
public static final int MONTH_FIELD

Useful constant for MONTH field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 2 (0x00000002)

SECOND_FIELD

Added in API level 1
public static final int SECOND_FIELD

Useful constant for SECOND field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 7 (0x00000007)

SHORT

Added in API level 1
public static final int SHORT

Constant for short style pattern.

Constant Value: 3 (0x00000003)

TIMEZONE_FIELD

Added in API level 1
public static final int TIMEZONE_FIELD

Useful constant for TIMEZONE field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 17 (0x00000011)

WEEK_OF_MONTH_FIELD

Added in API level 1
public static final int WEEK_OF_MONTH_FIELD

Useful constant for WEEK_OF_MONTH field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 13 (0x0000000d)

WEEK_OF_YEAR_FIELD

Added in API level 1
public static final int WEEK_OF_YEAR_FIELD

Useful constant for WEEK_OF_YEAR field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 12 (0x0000000c)

YEAR_FIELD

Added in API level 1
public static final int YEAR_FIELD

Useful constant for YEAR field alignment. Used in FieldPosition of date/time formatting.

Constant Value: 1 (0x00000001)

Fields

calendar

Added in API level 1
protected Calendar calendar

The Calendar instance used for calculating the date-time fields and the instant of time. This field is used for both formatting and parsing.

Subclasses should initialize this field to a Calendar appropriate for the Locale associated with this DateFormat.

numberFormat

Added in API level 1
protected NumberFormat numberFormat

The number formatter that DateFormat uses to format numbers in dates and times. Subclasses should initialize this to a number format appropriate for the locale associated with this DateFormat.

Protected constructors

DateFormat

Added in API level 1
protected DateFormat ()

Create a new date format.

Public methods

clone

Added in API level 1
public Object clone ()

Overrides Cloneable

Returns
Object a clone of this instance.

equals

Added in API level 1
public boolean equals (Object obj)

Overrides equals

Parameters
obj Object: the reference object with which to compare.

Returns
boolean true if this object is the same as the obj argument; false otherwise.

format

Added in API level 1
public final StringBuffer format (Object obj, 
                StringBuffer toAppendTo, 
                FieldPosition fieldPosition)

Formats the given Object into a date-time string. The formatted string is appended to the given StringBuffer.

Parameters
obj Object: Must be a Date or a Number representing a millisecond offset from the Epoch.

toAppendTo StringBuffer: The string buffer for the returning date-time string.

fieldPosition FieldPosition: keeps track on the position of the field within the returned string. For example, given a date-time text "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition is DateFormat#YEAR_FIELD, the begin index and end index of fieldPosition will be set to 0 and 4, respectively. Notice that if the same date-time field appears more than once in a pattern, the fieldPosition will be set for the first occurrence of that date-time field. For instance, formatting a Date to the date-time string "1 PM PDT (Pacific Daylight Time)" using the pattern "h a z (zzzz)" and the alignment field DateFormat#TIMEZONE_FIELD, the begin index and end index of fieldPosition will be set to 5 and 8, respectively, for the first occurrence of the timezone pattern character 'z'.

Returns
StringBuffer the string buffer passed in as toAppendTo, with formatted text appended.

Throws
IllegalArgumentException if the Format cannot format the given obj.

See also:

format

Added in API level 1
public abstract StringBuffer format (Date date, 
                StringBuffer toAppendTo, 
                FieldPosition fieldPosition)

Formats a Date into a date-time string. The formatted string is appended to the given StringBuffer.

Parameters
date Date: a Date to be formatted into a date-time string.

toAppendTo StringBuffer: the string buffer for the returning date-time string.

fieldPosition FieldPosition: keeps track on the position of the field within the returned string. For example, given a date-time text "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition is DateFormat#YEAR_FIELD, the begin index and end index of fieldPosition will be set to 0 and 4, respectively. Notice that if the same date-time field appears more than once in a pattern, the fieldPosition will be set for the first occurrence of that date-time field. For instance, formatting a Date to the date-time string "1 PM PDT (Pacific Daylight Time)" using the pattern "h a z (zzzz)" and the alignment field DateFormat#TIMEZONE_FIELD, the begin index and end index of fieldPosition will be set to 5 and 8, respectively, for the first occurrence of the timezone pattern character 'z'.

Returns
StringBuffer the string buffer passed in as toAppendTo, with formatted text appended.

format

Added in API level 1
public final String format (Date date)

Formats a Date into a date-time string.

Parameters
date Date: the time value to be formatted into a date-time string.

Returns
String the formatted date-time string.

getAvailableLocales

Added in API level 1
public static Locale[] getAvailableLocales ()

Returns an array of all locales for which the get*Instance methods of this class can return localized instances. It must contain at least a Locale instance equal to Locale.US.

Returns
Locale[] An array of locales for which localized DateFormat instances are available.

getCalendar

Added in API level 1
public Calendar getCalendar ()

Gets the calendar associated with this date/time formatter.

Returns
Calendar the calendar associated with this date/time formatter.

getDateInstance

Added in API level 1
public static final DateFormat getDateInstance (int style, 
                Locale aLocale)

Gets the date formatter with the given formatting style for the given locale.

Parameters
style int: the given formatting style. For example, SHORT for "M/d/yy" in the US locale.

aLocale Locale: the given locale.

Returns
DateFormat a date formatter.

getDateInstance

Added in API level 1
public static final DateFormat getDateInstance (int style)

Gets the date formatter with the given formatting style for the default FORMAT locale.

This is equivalent to calling getDateInstance(style, Locale.getDefault(Locale.Category.FORMAT)).

Parameters
style int: the given formatting style. For example, SHORT for "M/d/yy" in the US locale.

Returns
DateFormat a date formatter.

getDateInstance

Added in API level 1
public static final DateFormat getDateInstance ()

Gets the date formatter with the default formatting style for the default FORMAT locale.

This is equivalent to calling getDateInstance(DEFAULT, Locale.getDefault(Locale.Category.FORMAT)).

Returns
DateFormat a date formatter.

getDateTimeInstance

Added in API level 1
public static final DateFormat getDateTimeInstance (int dateStyle, 
                int timeStyle)

Gets the date/time formatter with the given date and time formatting styles for the default FORMAT locale.

This is equivalent to calling getDateTimeInstance(dateStyle, timeStyle, Locale.getDefault(Locale.Category.FORMAT)).

Parameters
dateStyle int: the given date formatting style. For example, SHORT for "M/d/yy" in the US locale.

timeStyle int: the given time formatting style. For example, SHORT for "h:mm a" in the US locale.

Returns
DateFormat a date/time formatter.

getDateTimeInstance

Added in API level 1
public static final DateFormat getDateTimeInstance (int dateStyle, 
                int timeStyle, 
                Locale aLocale)

Gets the date/time formatter with the given formatting styles for the given locale.

Parameters
dateStyle int: the given date formatting style.

timeStyle int: the given time formatting style.

aLocale Locale: the given locale.

Returns
DateFormat a date/time formatter.

getDateTimeInstance

Added in API level 1
public static final DateFormat getDateTimeInstance ()

Gets the date/time formatter with the default formatting style for the default FORMAT locale.

This is equivalent to calling getDateTimeInstance(DEFAULT, DEFAULT, Locale.getDefault(Locale.Category.FORMAT)).

Returns
DateFormat a date/time formatter.

getInstance

Added in API level 1
public static final DateFormat getInstance ()

Get a default date/time formatter that uses the SHORT style for both the date and the time.

Returns
DateFormat a date/time formatter

getNumberFormat

Added in API level 1
public NumberFormat getNumberFormat ()

Gets the number formatter which this date/time formatter uses to format and parse a time.

Returns
NumberFormat the number formatter which this date/time formatter uses.

getTimeInstance

Added in API level 1
public static final DateFormat getTimeInstance (int style)

Gets the time formatter with the given formatting style for the default FORMAT locale.

This is equivalent to calling getTimeInstance(style, Locale.getDefault(Locale.Category.FORMAT)).

Parameters
style int: the given formatting style. For example, SHORT for "h:mm a" in the US locale.

Returns
DateFormat a time formatter.

getTimeInstance

Added in API level 1
public static final DateFormat getTimeInstance (int style, 
                Locale aLocale)

Gets the time formatter with the given formatting style for the given locale.

Parameters
style int: the given formatting style. For example, SHORT for "h:mm a" in the US locale.

aLocale Locale: the given locale.

Returns
DateFormat a time formatter.

getTimeInstance

Added in API level 1
public static final DateFormat getTimeInstance ()

Gets the time formatter with the default formatting style for the default FORMAT locale.

This is equivalent to calling getTimeInstance(DEFAULT, Locale.getDefault(Locale.Category.FORMAT)).

Returns
DateFormat a time formatter.

getTimeZone

Added in API level 1
public TimeZone getTimeZone ()

Gets the time zone. This method is equivalent to the following call.

getCalendar().getTimeZone()
 

Returns
TimeZone the time zone associated with the calendar of DateFormat.

hashCode

Added in API level 1
public int hashCode ()

Overrides hashCode

Returns
int a hash code value for this object.

isLenient

Added in API level 1
public boolean isLenient ()

Tell whether date/time parsing is to be lenient. This method is equivalent to the following call.

getCalendar().isLenient()
 

Returns
boolean true if the calendar is lenient; false otherwise.

parse

Added in API level 1
public Date parse (String source)

Parses text from the beginning of the given string to produce a date. The method may not use the entire text of the given string.

See the parse(java.lang.String, java.text.ParsePosition) method for more information on date parsing.

Parameters
source String: A String whose beginning should be parsed.

Returns
Date A Date parsed from the string.

Throws
ParseException if the beginning of the specified string cannot be parsed.

parse

Added in API level 1
public abstract Date parse (String source, 
                ParsePosition pos)

Parse a date/time string according to the given parse position. For example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date that is equivalent to Date(837039900000L).

By default, parsing is lenient: If the input is not in the form used by this object's format method but can still be parsed as a date, then the parse succeeds. Clients may insist on strict adherence to the format by calling setLenient(false).

This parsing operation uses the calendar to produce a Date. As a result, the calendar's date-time fields and the TimeZone value may have been overwritten, depending on subclass implementations. Any TimeZone value that has previously been set by a call to setTimeZone may need to be restored for further operations.

Parameters
source String: The date/time string to be parsed

pos ParsePosition: On input, the position at which to start parsing; on output, the position at which parsing terminated, or the start position if the parse failed.

Returns
Date A Date, or null if the input could not be parsed

parseObject

Added in API level 1
public Object parseObject (String source, 
                ParsePosition pos)

Parses text from a string to produce a Date.

The method attempts to parse text starting at the index given by pos. If parsing succeeds, then the index of pos is updated to the index after the last character used (parsing does not necessarily use all characters up to the end of the string), and the parsed date is returned. The updated pos can be used to indicate the starting point for the next call to this method. If an error occurs, then the index of pos is not changed, the error index of pos is set to the index of the character where the error occurred, and null is returned.

See the parse(java.lang.String, java.text.ParsePosition) method for more information on date parsing.

Parameters
source String: A String, part of which should be parsed.

pos ParsePosition: A ParsePosition object with index and error index information as described above.

Returns
Object A Date parsed from the string. In case of error, returns null.

Throws
NullPointerException if source or pos is null.

setCalendar

Added in API level 1
public void setCalendar (Calendar newCalendar)

Set the calendar to be used by this date format. Initially, the default calendar for the specified or default locale is used.

Any TimeZone and leniency values that have previously been set are overwritten by newCalendar's values.

Parameters
newCalendar Calendar: the new Calendar to be used by the date format

setLenient

Added in API level 1
public void setLenient (boolean lenient)

Specify whether or not date/time parsing is to be lenient. With lenient parsing, the parser may use heuristics to interpret inputs that do not precisely match this object's format. With strict parsing, inputs must match this object's format.

This method is equivalent to the following call.

getCalendar().setLenient(lenient)
 

This leniency value is overwritten by a call to setCalendar().

Parameters
lenient boolean: when true, parsing is lenient

setNumberFormat

Added in API level 1
public void setNumberFormat (NumberFormat newNumberFormat)

Allows you to set the number formatter.

Parameters
newNumberFormat NumberFormat: the given new NumberFormat.

setTimeZone

Added in API level 1
public void setTimeZone (TimeZone zone)

Sets the time zone for the calendar of this DateFormat object. This method is equivalent to the following call.

getCalendar().setTimeZone(zone)
 

The TimeZone set by this method is overwritten by a setCalendar call.

The TimeZone set by this method may be overwritten as a result of a call to the parse method.

Parameters
zone TimeZone: the given new time zone.