SimpleDateFormat

public class SimpleDateFormat extends DateFormat

SimpleDateFormat is a concrete class for formatting and parsing dates in a locale-sensitive manner. It allows for formatting (date -> text), parsing (text -> date), and normalization.

SimpleDateFormat allows you to start by choosing any user-defined patterns for date-time formatting. However, you are encouraged to create a date-time formatter with either getTimeInstance, getDateInstance, or getDateTimeInstance in DateFormat. Each of these class methods can return a date/time formatter initialized with a default format pattern. You may modify the format pattern using the applyPattern methods as desired. For more information on using these methods, see DateFormat.

Date and Time Patterns

Date and time formats are specified by date and time pattern strings. Within date and time pattern strings, unquoted letters from 'A' to 'Z' and from 'a' to 'z' are interpreted as pattern letters representing the components of a date or time string. Text can be quoted using single quotes (') to avoid interpretation. "''" represents a single quote. All other characters are not interpreted; they're simply copied into the output string during formatting or matched against the input string during parsing.

The following pattern letters are defined (all other characters from 'A' to 'Z' and from 'a' to 'z' are reserved):

Letter	Date or Time Component	Presentation	Examples
G	Era designator	Text	AD
y	Year	Year	1996; 96
Y	Week year	Year	2009; 09
M	Month in year	Month	July; Jul; 07
w	Week in year	Number	27
W	Week in month	Number	2
D	Day in year	Number	189
d	Day in month	Number	10
F	Day of week in month	Number	2
E	Day name in week	Text	Tuesday; Tue
u	Day number of week (1 = Monday, ..., 7 = Sunday)	Number	1
a	Am/pm marker	Text	PM
H	Hour in day (0-23)	Number	0
k	Hour in day (1-24)	Number	24
K	Hour in am/pm (0-11)	Number	0
h	Hour in am/pm (1-12)	Number	12
m	Minute in hour	Number	30
s	Second in minute	Number	55
S	Millisecond	Number	978
z	Time zone	General time zone	Pacific Standard Time; PST; GMT-08:00
Z	Time zone	RFC 822 time zone	-0800
X	Time zone	ISO 8601 time zone	-08; -0800; -08:00

Pattern letters are usually repeated, as their number determines the exact presentation:

• Text: For formatting, if the number of pattern letters is 4 or more, the full form is used; otherwise a short or abbreviated form is used if available. For parsing, both forms are accepted, independent of the number of pattern letters.
  
  
• Number: For formatting, the number of pattern letters is the minimum number of digits, and shorter numbers are zero-padded to this amount. For parsing, the number of pattern letters is ignored unless it's needed to separate two adjacent fields.
  
  
• Year: If the formatter's Calendar is the Gregorian calendar, the following rules are applied.
  
  • For formatting, if the number of pattern letters is 2, the year is truncated to 2 digits; otherwise it is interpreted as a number.
  • For parsing, if the number of pattern letters is more than 2, the year is interpreted literally, regardless of the number of digits. So using the pattern "MM/dd/yyyy", "01/11/12" parses to Jan 11, 12 A.D.
  • For parsing with the abbreviated year pattern ("y" or "yy"), SimpleDateFormat must interpret the abbreviated year relative to some century. It does this by adjusting dates to be within 80 years before and 20 years after the time the SimpleDateFormat instance is created. For example, using a pattern of "MM/dd/yy" and a SimpleDateFormat instance created on Jan 1, 1997, the string "01/11/12" would be interpreted as Jan 11, 2012 while the string "05/04/64" would be interpreted as May 4, 1964. During parsing, only strings consisting of exactly two digits, as defined by Character.isDigit(char), will be parsed into the default century. Any other numeric string, such as a one digit string, a three or more digit string, or a two digit string that isn't all digits (for example, "-1"), is interpreted literally. So "01/02/3" or "01/02/003" are parsed, using the same pattern, as Jan 2, 3 AD. Likewise, "01/02/-3" is parsed as Jan 2, 4 BC.
  Otherwise, calendar system specific forms are applied. For both formatting and parsing, if the number of pattern letters is 4 or more, a calendar specific {@linkplain Calendar#LONG long form} is used. Otherwise, a calendar specific {@linkplain Calendar#SHORT short or abbreviated form} is used.
  
  If week year 'Y' is specified and the {@linkplain #getCalendar() calendar} doesn't support any week years, the calendar year ('y') is used instead. The support of week years can be tested with a call to getCalendar().isWeekDateSupported().
  
  
• Month: If the number of pattern letters is 3 or more, the month is interpreted as text; otherwise, it is interpreted as a number.
  
  
• General time zone: Time zones are interpreted as text if they have names. For time zones representing a GMT offset value, the following syntax is used:

       GMTOffsetTimeZone:
               GMT Sign Hours : Minutes
       Sign: one of
               + -
       Hours:
               Digit
               Digit Digit
       Minutes:
               Digit Digit
       Digit: one of
               0 1 2 3 4 5 6 7 8 9

  Hours must be between 0 and 23, and Minutes must be between 00 and 59. The format is locale independent and digits must be taken from the Basic Latin block of the Unicode standard.

  For parsing, RFC 822 time zones are also accepted.
  
  

• RFC 822 time zone: For formatting, the RFC 822 4-digit time zone format is used:

       RFC822TimeZone:
               Sign TwoDigitHours Minutes
       TwoDigitHours:
               Digit Digit

  TwoDigitHours must be between 00 and 23. Other definitions are as for general time zones.

  For parsing, general time zones are also accepted.

• ISO 8601 Time zone: The number of pattern letters designates the format for both formatting and parsing as follows:

       ISO8601TimeZone:
               OneLetterISO8601TimeZone
               TwoLetterISO8601TimeZone
               ThreeLetterISO8601TimeZone
       OneLetterISO8601TimeZone:
               Sign TwoDigitHours
               Z
       TwoLetterISO8601TimeZone:
               Sign TwoDigitHours Minutes
               Z
       ThreeLetterISO8601TimeZone:
               Sign TwoDigitHours : Minutes
               Z

  Other definitions are as for general time zones or RFC 822 time zones.

  For formatting, if the offset value from GMT is 0, "Z" is produced. If the number of pattern letters is 1, any fraction of an hour is ignored. For example, if the pattern is "X" and the time zone is "GMT+05:30", "+05" is produced.

  For parsing, "Z" is parsed as the UTC time zone designator. General time zones are not accepted.

  If the number of pattern letters is 4 or more, IllegalArgumentException is thrown when constructing a SimpleDateFormat or {@linkplain #applyPattern(String) applying a pattern}.

SimpleDateFormat also supports localized date and time pattern strings. In these strings, the pattern letters described above may be replaced with other, locale dependent, pattern letters. SimpleDateFormat does not deal with the localization of text other than the pattern letters; that's up to the client of the class.

Examples

The following examples show how date and time patterns are interpreted in the U.S. locale. The given date and time are 2001-07-04 12:08:56 local time in the U.S. Pacific Time time zone.

Date and Time Pattern	Result
"yyyy.MM.dd G 'at' HH:mm:ss z"	2001.07.04 AD at 12:08:56 PDT
"EEE, MMM d, ''yy"	Wed, Jul 4, '01
"h:mm a"	12:08 PM
"hh 'o''clock' a, zzzz"	12 o'clock PM, Pacific Daylight Time
"K:mm a, z"	0:08 PM, PDT
"yyyyy.MMMM.dd GGG hh:mm aaa"	02001.July.04 AD 12:08 PM
"EEE, d MMM yyyy HH:mm:ss Z"	Wed, 4 Jul 2001 12:08:56 -0700
"yyMMddHHmmssZ"	010704120856-0700
"yyyy-MM-dd'T'HH:mm:ss.SSSZ"	2001-07-04T12:08:56.235-0700
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX"	2001-07-04T12:08:56.235-07:00
"YYYY-'W'ww-u"	2001-W27-3

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.

See Also

• Java Tutorial
• Calendar
• TimeZone
• DateFormat
• DateFormatSymbols

Inherited Constant Summary

From class java.text.DateFormat

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.

Inherited Field Summary

From class java.text.DateFormat

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.

Public Constructor Summary

	SimpleDateFormat() Constructs a SimpleDateFormat using the default pattern and date format symbols for the default locale.
	SimpleDateFormat(String pattern) Constructs a SimpleDateFormat using the given pattern and the default date format symbols for the default locale.
	SimpleDateFormat(String pattern, Locale locale) Constructs a SimpleDateFormat using the given pattern and the default date format symbols for the given locale.
	SimpleDateFormat(String pattern, DateFormatSymbols formatSymbols) Constructs a SimpleDateFormat using the given pattern and date format symbols.

Public Method Summary

void	applyLocalizedPattern(String pattern) Applies the given localized pattern string to this date format.
void	applyPattern(String pattern) Applies the given pattern string to this date format.
Object	clone() Creates a copy of this SimpleDateFormat.
boolean	equals(Object obj) Compares the given object with this SimpleDateFormat for equality.
StringBuffer	format(Date date, StringBuffer toAppendTo, FieldPosition pos) Formats the given Date into a date/time string and appends the result to the given StringBuffer.
AttributedCharacterIterator	formatToCharacterIterator(Object obj) Formats an Object producing an AttributedCharacterIterator.
Date	get2DigitYearStart() Returns the beginning date of the 100-year period 2-digit years are interpreted as being within.
DateFormatSymbols	getDateFormatSymbols() Gets a copy of the date and time format symbols of this date format.
int	hashCode() Returns the hash code value for this SimpleDateFormat object.
Date	parse(String text, ParsePosition pos) Parses text from a string to produce a Date.
void	set2DigitYearStart(Date startDate) Sets the 100-year period 2-digit years will be interpreted as being in to begin on the date the user specifies.
void	setDateFormatSymbols(DateFormatSymbols newFormatSymbols) Sets the date and time format symbols of this date format.
String	toLocalizedPattern() Returns a localized pattern string describing this date format.
String	toPattern() Returns a pattern string describing this date format.

Inherited Method Summary

From class java.text.DateFormat

Object	clone() Overrides Cloneable
boolean	equals(Object obj) Overrides equals
final StringBuffer	format(Object obj, StringBuffer toAppendTo, FieldPosition fieldPosition) Overrides Format.
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.
final static DateFormat	getDateInstance(int style, Locale aLocale) Gets the date formatter with the given formatting style for the given locale.
final static DateFormat	getDateInstance(int style) Gets the date formatter with the given formatting style for the default FORMAT locale.
final static DateFormat	getDateInstance() Gets the date formatter with the default formatting style for the default FORMAT locale.
final static DateFormat	getDateTimeInstance(int dateStyle, int timeStyle) Gets the date/time formatter with the given date and time formatting styles for the default FORMAT locale.
final static DateFormat	getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale) Gets the date/time formatter with the given formatting styles for the given locale.
final static DateFormat	getDateTimeInstance() Gets the date/time formatter with the default formatting style for the default FORMAT locale.
final static 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.
final static DateFormat	getTimeInstance(int style) Gets the time formatter with the given formatting style for the default FORMAT locale.
final static DateFormat	getTimeInstance(int style, Locale aLocale) Gets the time formatter with the given formatting style for the given locale.
final static 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.

From class java.text.Format

Object	clone() Creates and returns a copy of this object.
final String	format(Object obj) Formats an object to produce a string.
abstract StringBuffer	format(Object obj, StringBuffer toAppendTo, FieldPosition pos) Formats an object and appends the resulting text to a given string buffer.
AttributedCharacterIterator	formatToCharacterIterator(Object obj) Formats an Object producing an AttributedCharacterIterator.
Object	parseObject(String source) Parses text from the beginning of the given string to produce an object.
abstract Object	parseObject(String source, ParsePosition pos) Parses text from a string to produce an object.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public SimpleDateFormat ()

Constructs a SimpleDateFormat using the default pattern and date format symbols for the default locale. Note: This constructor may not support all locales. For full coverage, use the factory methods in the DateFormat class.

public SimpleDateFormat (String pattern)

Constructs a SimpleDateFormat using the given pattern and the default date format symbols for the default locale. Note: This constructor may not support all locales. For full coverage, use the factory methods in the DateFormat class.

Parameters

pattern	the pattern describing the date and time format

Throws

NullPointerException	if the given pattern is null
IllegalArgumentException	if the given pattern is invalid

public SimpleDateFormat (String pattern, Locale locale)

Constructs a SimpleDateFormat using the given pattern and the default date format symbols for the given locale. Note: This constructor may not support all locales. For full coverage, use the factory methods in the DateFormat class.

Parameters

pattern	the pattern describing the date and time format
locale	the locale whose date format symbols should be used

Throws

NullPointerException	if the given pattern or locale is null
IllegalArgumentException	if the given pattern is invalid

public SimpleDateFormat (String pattern, DateFormatSymbols formatSymbols)

Constructs a SimpleDateFormat using the given pattern and date format symbols.

Parameters

pattern	the pattern describing the date and time format
formatSymbols	the date format symbols to be used for formatting

Throws

NullPointerException	if the given pattern or formatSymbols is null
IllegalArgumentException	if the given pattern is invalid

Public Methods

public void applyLocalizedPattern (String pattern)

Applies the given localized pattern string to this date format.

Parameters

pattern	a String to be mapped to the new date and time format pattern for this format

Throws

NullPointerException	if the given pattern is null
IllegalArgumentException	if the given pattern is invalid

public void applyPattern (String pattern)

Applies the given pattern string to this date format.

Parameters

pattern	the new date and time pattern for this date format

Throws

NullPointerException	if the given pattern is null
IllegalArgumentException	if the given pattern is invalid

public Object clone ()

Creates a copy of this SimpleDateFormat. This also clones the format's date format symbols.

Returns

• a clone of this SimpleDateFormat

public boolean equals (Object obj)

Compares the given object with this SimpleDateFormat for equality.

Parameters

obj	the object to compare this instance with.

Returns

• true if the given object is equal to this SimpleDateFormat

public StringBuffer format (Date date, StringBuffer toAppendTo, FieldPosition pos)

Formats the given Date into a date/time string and appends the result to the given StringBuffer.

Parameters

date	the date-time value to be formatted into a date-time string.
toAppendTo	where the new date-time text is to be appended.
pos	the formatting position. On input: an alignment field, if desired. On output: the offsets of the alignment field.

Returns

• the formatted date-time string.

Throws

NullPointerException	if the given date is null.

public AttributedCharacterIterator formatToCharacterIterator (Object obj)

Formats an Object producing an AttributedCharacterIterator. You can use the returned AttributedCharacterIterator to build the resulting String, as well as to determine information about the resulting String.

Each attribute key of the AttributedCharacterIterator will be of type DateFormat.Field, with the corresponding attribute value being the same as the attribute key.

Parameters

obj	The object to format

Returns

• AttributedCharacterIterator describing the formatted value.

Throws

NullPointerException	if obj is null.
IllegalArgumentException	if the Format cannot format the given object, or if the Format's pattern string is invalid.

public Date get2DigitYearStart ()

Returns the beginning date of the 100-year period 2-digit years are interpreted as being within.

Returns

• the start of the 100-year period into which two digit years are parsed

See Also

• set2DigitYearStart(Date)

public DateFormatSymbols getDateFormatSymbols ()

Gets a copy of the date and time format symbols of this date format.

Returns

• the date and time format symbols of this date format

See Also

• setDateFormatSymbols(DateFormatSymbols)

public int hashCode ()

Returns the hash code value for this SimpleDateFormat object.

Returns

• the hash code value for this SimpleDateFormat object.

public Date parse (String text, 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.

This parsing operation uses the calendar to produce a Date. All of the calendar's date-time fields are {@linkplain Calendar#clear() cleared} before parsing, and the calendar's default values of the date-time fields are used for any missing date-time information. For example, the year value of the parsed Date is 1970 with GregorianCalendar if no year value is given from the parsing operation. The TimeZone value may be overwritten, depending on the given pattern and the time zone value in text. Any TimeZone value that has previously been set by a call to setTimeZone may need to be restored for further operations.

Parameters

text	A String, part of which should be parsed.
pos	A ParsePosition object with index and error index information as described above.

Returns

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

Throws

NullPointerException	if text or pos is null.

public void set2DigitYearStart (Date startDate)

Sets the 100-year period 2-digit years will be interpreted as being in to begin on the date the user specifies.

Parameters

startDate	During parsing, two digit years will be placed in the range startDate to startDate + 100 years.

See Also

• get2DigitYearStart()

public void setDateFormatSymbols (DateFormatSymbols newFormatSymbols)

Sets the date and time format symbols of this date format.

Parameters

newFormatSymbols	the new date and time format symbols

Throws

NullPointerException	if the given newFormatSymbols is null

See Also

• getDateFormatSymbols()

public String toLocalizedPattern ()

Returns a localized pattern string describing this date format.

Returns

• a localized pattern string describing this date format.

public String toPattern ()

Returns a pattern string describing this date format.

Returns

• a pattern string describing this date format.