SimpleDateFormat

public class SimpleDateFormat
extends DateFormat

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

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

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 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.
    • Letter M produces context-sensitive month names, such as the embedded form of names. If a DateFormatSymbols has been set explicitly with constructor SimpleDateFormat(java.lang.String, java.text.DateFormatSymbols) or method setDateFormatSymbols(java.text.DateFormatSymbols), the month names given by the DateFormatSymbols are used.
    • Letter L produces the standalone form of month names.

  • 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, the letter "Z" is parsed as the UTC time zone designator (therefore "09:30Z" is parsed as "09:30 UTC". General time zones are not accepted.

    If the number of "X" pattern letters is 4 or more (e.g. XXXX), IllegalArgumentException is thrown when constructing a SimpleDateFormat or 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.

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.

Public constructors
SimpleDateFormat()

Constructs a SimpleDateFormat using the default pattern and date format symbols for the default FORMAT locale.

SimpleDateFormat(String pattern)

Constructs a SimpleDateFormat using the given pattern and the default date format symbols for the default FORMAT 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 methods
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 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 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.

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 timeout, 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 timeout)

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

public SimpleDateFormat ()

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

SimpleDateFormat

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 String: the pattern describing the date and time format
locale 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

SimpleDateFormat

public SimpleDateFormat (String pattern,                  DateFormatSymbols formatSymbols)

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

Parameters
pattern String: the pattern describing the date and time format
formatSymbols DateFormatSymbols: 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

applyLocalizedPattern

public void applyLocalizedPattern (String pattern)

Applies the given localized pattern string to this date format.

Parameters
pattern String: 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

applyPattern

public void applyPattern (String pattern)

Applies the given pattern string to this date format.

Parameters
pattern String: 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

clone

public Object clone ()

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

Returns
Object a clone of this SimpleDateFormat

equals

public boolean equals (Object obj)

Compares the given object with this SimpleDateFormat for equality.

Parameters
obj Object: the reference object with which to compare.
Returns
boolean true if the given object is equal to this SimpleDateFormat

format

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

formatToCharacterIterator

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 Object: The object to format
Returns
AttributedCharacterIterator 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.

get2DigitYearStart

public Date get2DigitYearStart ()

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

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

getDateFormatSymbols

public DateFormatSymbols getDateFormatSymbols ()

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

Returns
DateFormatSymbols the date and time format symbols of this date format

hashCode

public int hashCode ()

Returns the hash code value for this SimpleDateFormat object.

Returns
int the hash code value for this SimpleDateFormat object.

parse

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 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 String: A String, part of which should be parsed.
pos ParsePosition: A ParsePosition object with index and error index information as described above.
Returns
Date A Date parsed from the string. In case of error, returns null.
Throws
NullPointerException if text or pos is null.

set2DigitYearStart

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

setDateFormatSymbols

public void setDateFormatSymbols (DateFormatSymbols newFormatSymbols)

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

Parameters
newFormatSymbols DateFormatSymbols: the new date and time format symbols
Throws
NullPointerException if the given newFormatSymbols is null

toLocalizedPattern

public String toLocalizedPattern ()

Returns a localized pattern string describing this date format.

Returns
String a localized pattern string describing this date format.

toPattern

public String toPattern ()

Returns a pattern string describing this date format.

Returns
String a pattern string describing this date format.

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Last updated 2021-02-18 UTC.