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

• 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 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 long form is used. Otherwise, a calendar specific short or abbreviated form is used.
  
  If week year 'Y' is specified and the 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 applying a pattern.

Examples

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.MMMMM.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.

Summary

Inherited constants

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 fields
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.

Inherited methods
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. 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 locale. static final DateFormat getDateInstance() Gets the date formatter with the default formatting style for the default 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 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 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 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 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) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long millis, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. final void wait(long millis) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed. final void wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object.

Public constructors

SimpleDateFormat ()

SimpleDateFormat (String pattern)

SimpleDateFormat (String pattern, 
                Locale locale)

SimpleDateFormat (String pattern, 
                DateFormatSymbols formatSymbols)

Public methods

void applyLocalizedPattern (String pattern)

void applyPattern (String pattern)

Object clone ()

boolean equals (Object obj)

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

AttributedCharacterIterator formatToCharacterIterator (Object obj)

Date get2DigitYearStart ()

DateFormatSymbols getDateFormatSymbols ()

int hashCode ()

Date parse (String text, 
                ParsePosition pos)

void set2DigitYearStart (Date startDate)

void setDateFormatSymbols (DateFormatSymbols newFormatSymbols)

String toLocalizedPattern ()

String toPattern ()