SimpleDateFormat


public class SimpleDateFormat
extends DateFormat

java.lang.Object
   ↳ java.text.Format
     ↳ android.icu.text.UFormat
       ↳ android.icu.text.DateFormat
         ↳ android.icu.text.SimpleDateFormat


[icu enhancement] ICU's replacement for SimpleDateFormat. Methods, fields, and other functionality specific to ICU are labeled '[icu]'.

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.

Clients are encouraged to create a date-time formatter using DateFormat.getDateInstance(), DateFormat.getDateInstance(), or DateFormat.getDateTimeInstance() rather than explicitly constructing an instance of SimpleDateFormat. This way, the client is guaranteed to get an appropriate formatting pattern for whatever locale the program is running in. If the client needs more control, they should consider using DateFormat.getInstanceForSkeleton(). However, if the client needs something more unusual than the default patterns in the locales, he can construct a SimpleDateFormat directly and give it an appropriate pattern (or use one of the factory methods on DateFormat and modify the pattern after the fact with toPattern() and applyPattern(). 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. The full syntax for date and time patterns can be found at https://unicode.org/reports/tr35/tr35-dates.html#Date_Format_Patterns.

Within date and time pattern strings, all unquoted ASCII letters [A-Za-z] are reserved as pattern letters representing calendar fields. Some of the most commonly used pattern letters are:

Sym. No. Example Description
G 1..3 AD Era - Replaced with the Era string for the current date. One to three letters for the abbreviated form, four letters for the long (wide) form, five for the narrow form.
y 1..n 1996 Year. Normally the length specifies the padding, but for two letters it also specifies the maximum length. Example:
Year y yy yyy yyyy yyyyy
AD 1 1 01 001 0001 00001
AD 12 12 12 012 0012 00012
AD 123 123 23 123 0123 00123
AD 1234 1234 34 1234 1234 01234
AD 12345 12345 45 12345 12345 12345
Q 1..2 02 Quarter - Use one or two for the numerical quarter, three for the abbreviation, or four for the full (wide) name (five for the narrow name is not yet supported).
3 Q2
4 2nd quarter
M 1..2 09 Month - Use one or two for the numerical month, three for the abbreviation, four for the full (wide) name, or five for the narrow name. With two ("MM"), the month number is zero-padded if necessary (e.g. "08").
3 Sep
4 September
5 S
d 1..2 1 Date - Day of the month. Use "d" to show the minimum number of digits, or "dd" to always show two digits (zero-padding if necessary, e.g. "08").
E 1..3 Tue Day of week - Use one through three letters for the short day, four for the full (wide) name, five for the narrow name, or six for the short name.
4 Tuesday
5 T
6 Tu
a 1 AM AM or PM
h 1..2 11 Hour [1-12]. When used in skeleton data or in a skeleton passed in an API for flexible data pattern generation, it should match the 12-hour-cycle format preferred by the locale (h or K); it should not match a 24-hour-cycle format (H or k). Use hh for zero padding.
H 1..2 13 Hour [0-23]. When used in skeleton data or in a skeleton passed in an API for flexible data pattern generation, it should match the 24-hour-cycle format preferred by the locale (H or k); it should not match a 12-hour-cycle format (h or K). Use HH for zero padding.
m 1..2 59 Minute. Use "m" to show the minimum number of digits, or "mm" to always show two digits (zero-padding if necessary, e.g. "08")..
s 1..2 12 Second. Use "s" to show the minimum number of digits, or "ss" to always show two digits (zero-padding if necessary, e.g. "08").
z 1..3 PDT Time zone. The short specific non-location format. Where that is unavailable, falls back to the short localized GMT format ("O").
4 Pacific Daylight Time The long specific non-location format. Where that is unavailable, falls back to the long localized GMT format ("OOOO").
v 1 PT Time zone. The short generic non-location format. Where that is unavailable, falls back to the generic location format ("VVVV"), then the short localized GMT format as the final fallback.
4 Pacific Time The long generic non-location format. Where that is unavailable, falls back to generic location format ("VVVV").

Any characters in the pattern that are not in the ranges of ['a'..'z'] and ['A'..'Z'] will be treated as quoted text. For instance, characters like ':', '.', ' ', '#' and '@' will appear in the resulting time text even they are not embraced within single quotes.

A pattern containing any invalid pattern letter will result in a thrown exception during formatting or parsing.

Examples Using the US Locale:

 Format Pattern                         Result
 --------------                         -------
 "yyyy.MM.dd G 'at' HH:mm:ss vvvv" ->>  1996.07.10 AD at 15:08:56 Pacific Time
 "EEE, MMM d, ''yy"                ->>  Wed, July 10, '96
 "h:mm a"                          ->>  12:08 PM
 "hh 'o''clock' a, zzzz"           ->>  12 o'clock PM, Pacific Daylight Time
 "K:mm a, vvv"                     ->>  0:00 PM, PT
 "yyyyy.MMMMM.dd GGG hh:mm aaa"    ->>  01996.July.10 AD 12:08 PM
 
Code Sample:
 SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, "PST");
 pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2*60*60*1000);
 pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2*60*60*1000);
 
// Format the current time. SimpleDateFormat formatter = new SimpleDateFormat ("yyyy.MM.dd G 'at' hh:mm:ss a zzz"); Date currentTime_1 = new Date(); String dateString = formatter.format(currentTime_1);
// Parse the previous string back into a Date. ParsePosition pos = new ParsePosition(0); Date currentTime_2 = formatter.parse(dateString, pos);
In the example, the time value currentTime_2 obtained from parsing will be equal to currentTime_1. However, they may not be equal if the am/pm marker 'a' is left out from the format pattern while the "hour in am/pm" pattern symbol is used. This information loss can happen when formatting the time in PM.

When parsing a date string using the abbreviated year pattern ("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 UCharacter.isDigit(int), 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.

If the year pattern does not have exactly two 'y' characters, 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.

When numeric fields abut one another directly, with no intervening delimiter characters, they constitute a run of abutting numeric fields. Such runs are parsed specially. For example, the format "HHmmss" parses the input text "123456" to 12:34:56, parses the input text "12345" to 1:23:45, and fails to parse "1234". In other words, the leftmost field of the run is flexible, while the others keep a fixed width. If the parse fails anywhere in the run, then the leftmost field is shortened by one character, and the entire run is parsed again. This is repeated until either the parse succeeds or the leftmost field is one character in length. If the parse still fails at that point, the parse of the run fails.

For time zones that have no names, use strings GMT+hours:minutes or GMT-hours:minutes.

The calendar defines what is the first day of the week, the first week of the year, whether hours are zero based or not (0 vs 12 or 24), and the time zone. There is one common decimal format to handle all the numbers; the digit count is handled programmatically according to the pattern.

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

Inherited fields

Public constructors

SimpleDateFormat()

Constructs a SimpleDateFormat using the default pattern for the default FORMAT locale.

SimpleDateFormat(String pattern)

Constructs a SimpleDateFormat using the given pattern in the default FORMAT locale.

SimpleDateFormat(String pattern, Locale loc)

Constructs a SimpleDateFormat using the given pattern and locale.

SimpleDateFormat(String pattern, ULocale loc)

Constructs a SimpleDateFormat using the given pattern and locale.

SimpleDateFormat(String pattern, String override, ULocale loc)

Constructs a SimpleDateFormat using the given pattern , override and locale.

SimpleDateFormat(String pattern, DateFormatSymbols formatData)

Constructs a SimpleDateFormat using the given pattern and locale-specific symbol data.

Public methods

void applyLocalizedPattern(String pat)

Apply the given localized pattern string to this date format.

void applyPattern(String pat)

Apply the given unlocalized pattern string to this date format.

Object clone()

Overrides Cloneable

boolean equals(Object obj)

Override equals.

StringBuffer format(Calendar cal, StringBuffer toAppendTo, FieldPosition pos)

Formats a date or time, which is the standard millis since January 1, 1970, 00:00:00 GMT.

AttributedCharacterIterator formatToCharacterIterator(Object obj)

Format the object to an attributed string, and return the corresponding iterator Overrides superclass method.

Date get2DigitYearStart()

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

DateFormatSymbols getDateFormatSymbols()

Gets the date/time formatting data.

NumberFormat getNumberFormat(char field)

give the NumberFormat used for the field like 'y'(year) and 'M'(year)

TimeZoneFormat getTimeZoneFormat()

[icu] Gets the time zone formatter which this date/time formatter uses to format and parse a time zone.

int hashCode()

Override hashCode.

void parse(String text, Calendar cal, ParsePosition parsePos)

Overrides DateFormat

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 setContext(DisplayContext context)

[icu] Set a particular DisplayContext value in the formatter, such as CAPITALIZATION_FOR_STANDALONE.

void setDateFormatSymbols(DateFormatSymbols newFormatSymbols)

Allows you to set the date/time formatting data.

void setNumberFormat(String fields, NumberFormat overrideNF)

allow the user to set the NumberFormat for several fields It can be a single field like: "y"(year) or "M"(month) It can be several field combined together: "yMd"(year, month and date) Note: 1 symbol field is enough for multiple symbol fields (so "y" will override "yy", "yyy") If the field is not numeric, then override has no effect (like "MMM" will use abbreviation, not numerical field)

void setNumberFormat(NumberFormat newNumberFormat)

Overrides superclass method and This method also clears per field NumberFormat instances previously set by setNumberFormat(java.lang.String, android.icu.text.NumberFormat)

void setTimeZoneFormat(TimeZoneFormat tzfmt)

[icu] Allows you to set the time zone formatter.

String toLocalizedPattern()

Return a localized pattern string describing this date format.

String toPattern()

Return a pattern string describing this date format.

Protected methods

DateFormatSymbols getSymbols()

Method for subclasses to access the DateFormatSymbols.

int matchQuarterString(String text, int start, int field, String[] data, Calendar cal)

Attempt to match the text at a given position against an array of quarter strings.

int matchString(String text, int start, int field, String[] data, Calendar cal)

Attempt to match the text at a given position against an array of strings.

DateFormat.Field patternCharToDateFormatField(char ch)

Returns a DateFormat.Field constant associated with the specified format pattern character.

String subFormat(char ch, int count, int beginOffset, FieldPosition pos, DateFormatSymbols fmtData, Calendar cal)

Formats a single field, given its pattern character.

int subParse(String text, int start, char ch, int count, boolean obeyCount, boolean allowNegative, boolean[] ambiguousYear, Calendar cal)

Protected method that converts one field of the input string into a numeric field value in cal.

String zeroPaddingNumber(long value, int minDigits, int maxDigits)

Formats a number with the specified minimum and maximum number of digits.

Inherited methods

Public constructors

SimpleDateFormat

Added in API level 24
public SimpleDateFormat ()

Constructs a SimpleDateFormat using the default pattern for the default FORMAT locale. Note: Not all locales support SimpleDateFormat; for full generality, use the factory methods in the DateFormat class.

SimpleDateFormat

Added in API level 24
public SimpleDateFormat (String pattern)

Constructs a SimpleDateFormat using the given pattern in the default FORMAT locale. Note: Not all locales support SimpleDateFormat; for full generality, use the factory methods in the DateFormat class.

Parameters
pattern String

SimpleDateFormat

Added in API level 24
public SimpleDateFormat (String pattern, 
                Locale loc)

Constructs a SimpleDateFormat using the given pattern and locale. Note: Not all locales support SimpleDateFormat; for full generality, use the factory methods in the DateFormat class.

Parameters
pattern String

loc Locale

SimpleDateFormat

Added in API level 24
public SimpleDateFormat (String pattern, 
                ULocale loc)

Constructs a SimpleDateFormat using the given pattern and locale. Note: Not all locales support SimpleDateFormat; for full generality, use the factory methods in the DateFormat class.

Parameters
pattern String

loc ULocale

SimpleDateFormat

Added in API level 24
public SimpleDateFormat (String pattern, 
                String override, 
                ULocale loc)

Constructs a SimpleDateFormat using the given pattern , override and locale.

Parameters
pattern String: The pattern to be used

override String: The override string. A numbering system override string can take one of the following forms: 1). If just a numbering system name is specified, it applies to all numeric fields in the date format pattern. 2). To specify an alternate numbering system on a field by field basis, use the field letters from the pattern followed by an = sign, followed by the numbering system name. For example, to specify that just the year be formatted using Hebrew digits, use the override "y=hebr". Multiple overrides can be specified in a single string by separating them with a semi-colon. For example, the override string "m=thai;y=deva" would format using Thai digits for the month and Devanagari digits for the year.

loc ULocale: The locale to be used

SimpleDateFormat

Added in API level 24
public SimpleDateFormat (String pattern, 
                DateFormatSymbols formatData)

Constructs a SimpleDateFormat using the given pattern and locale-specific symbol data. Warning: uses default FORMAT locale for digits!

Parameters
pattern String

formatData DateFormatSymbols

Public methods

applyLocalizedPattern

Added in API level 24
public void applyLocalizedPattern (String pat)

Apply the given localized pattern string to this date format.

Parameters
pat String

applyPattern

Added in API level 24
public void applyPattern (String pat)

Apply the given unlocalized pattern string to this date format.

Parameters
pat String

clone

Added in API level 24
public Object clone ()

Overrides Cloneable

Returns
Object a clone of this instance.

equals

Added in API level 24
public boolean equals (Object obj)

Override 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 24
public StringBuffer format (Calendar cal, 
                StringBuffer toAppendTo, 
                FieldPosition pos)

Formats a date or time, which is the standard millis since January 1, 1970, 00:00:00 GMT.

Example: using the US locale: "yyyy.MM.dd G 'at' HH:mm:ss zzz" ->> 1996.07.10 AD at 15:08:56 PDT

Parameters
cal Calendar: the calendar whose date-time value is 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.

See also:

formatToCharacterIterator

Added in API level 24
public AttributedCharacterIterator formatToCharacterIterator (Object obj)

Format the object to an attributed string, and return the corresponding iterator Overrides superclass method.

Parameters
obj Object: The object to format

Returns
AttributedCharacterIterator AttributedCharacterIterator describing the formatted value.

get2DigitYearStart

Added in API level 24
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

Added in API level 24
public DateFormatSymbols getDateFormatSymbols ()

Gets the date/time formatting data.

Returns
DateFormatSymbols a copy of the date-time formatting data associated with this date-time formatter.

getNumberFormat

Added in API level 24
public NumberFormat getNumberFormat (char field)

give the NumberFormat used for the field like 'y'(year) and 'M'(year)

Parameters
field char: the field the user wants

Returns
NumberFormat override NumberFormat used for the field

getTimeZoneFormat

Added in API level 24
public TimeZoneFormat getTimeZoneFormat ()

[icu] Gets the time zone formatter which this date/time formatter uses to format and parse a time zone.

Returns
TimeZoneFormat the time zone formatter which this date/time formatter uses.

hashCode

Added in API level 24
public int hashCode ()

Override hashCode. Generates the hash code for the SimpleDateFormat object

Returns
int a hash code value for this object.

parse

Added in API level 24
public void parse (String text, 
                Calendar cal, 
                ParsePosition parsePos)

Overrides DateFormat

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

cal Calendar: The calendar set on input to the date and time to be used for missing values in the date/time string being parsed, and set on output to the parsed date/time. In general, this should be initialized before calling this method - either cleared or set to the current date, depending on desired behavior. If this parse fails, the calendar may still have been modified. When the calendar type is different from the internal calendar held by this DateFormat instance, calendar field values will be parsed based on the internal calendar initialized with the time and the time zone taken from this calendar, then the parse result (time in milliseconds and time zone) will be set back to this calendar.

parsePos 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.

See also:

set2DigitYearStart

Added in API level 24
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.

setContext

Added in API level 24
public void setContext (DisplayContext context)

[icu] Set a particular DisplayContext value in the formatter, such as CAPITALIZATION_FOR_STANDALONE. Note: For getContext, see DateFormat.

Parameters
context DisplayContext: The DisplayContext value to set.

setDateFormatSymbols

Added in API level 24
public void setDateFormatSymbols (DateFormatSymbols newFormatSymbols)

Allows you to set the date/time formatting data.

Parameters
newFormatSymbols DateFormatSymbols: the new symbols

setNumberFormat

Added in API level 24
public void setNumberFormat (String fields, 
                NumberFormat overrideNF)

allow the user to set the NumberFormat for several fields It can be a single field like: "y"(year) or "M"(month) It can be several field combined together: "yMd"(year, month and date) Note: 1 symbol field is enough for multiple symbol fields (so "y" will override "yy", "yyy") If the field is not numeric, then override has no effect (like "MMM" will use abbreviation, not numerical field)

Parameters
fields String: the fields to override

overrideNF NumberFormat: the NumbeferFormat used

Throws
IllegalArgumentException when the fields contain invalid field

setNumberFormat

Added in API level 24
public void setNumberFormat (NumberFormat newNumberFormat)

Overrides superclass method and This method also clears per field NumberFormat instances previously set by setNumberFormat(java.lang.String, android.icu.text.NumberFormat)

Parameters
newNumberFormat NumberFormat: the given new NumberFormat.

setTimeZoneFormat

Added in API level 24
public void setTimeZoneFormat (TimeZoneFormat tzfmt)

[icu] Allows you to set the time zone formatter.

Parameters
tzfmt TimeZoneFormat: the new time zone formatter

toLocalizedPattern

Added in API level 24
public String toLocalizedPattern ()

Return a localized pattern string describing this date format.

Note: This implementation depends on DateFormatSymbols#getLocalPatternChars() to get localized format pattern characters. ICU does not include localized pattern character data, therefore, unless user sets localized pattern characters manually, this method returns the same result as toPattern().

Returns
String

toPattern

Added in API level 24
public String toPattern ()

Return a pattern string describing this date format.

Returns
String

Protected methods

getSymbols

Added in API level 24
protected DateFormatSymbols getSymbols ()

Method for subclasses to access the DateFormatSymbols.

Returns
DateFormatSymbols

matchQuarterString

Added in API level 24
protected int matchQuarterString (String text, 
                int start, 
                int field, 
                String[] data, 
                Calendar cal)

Attempt to match the text at a given position against an array of quarter strings. Since multiple strings in the array may match (for example, if the array contains "a", "ab", and "abc", all will match the input string "abcd") the longest match is returned. As a side effect, the given field of cal is set to the index of the best match, if there is one.

Parameters
text String: the time text being parsed.

start int: where to start parsing.

field int: the date field being parsed.

data String: the string array to parsed.

cal Calendar

Returns
int the new start position if matching succeeded; a negative number indicating matching failure, otherwise. As a side effect, sets the cal field field to the index of the best match, if matching succeeded.

matchString

Added in API level 24
protected int matchString (String text, 
                int start, 
                int field, 
                String[] data, 
                Calendar cal)

Attempt to match the text at a given position against an array of strings. Since multiple strings in the array may match (for example, if the array contains "a", "ab", and "abc", all will match the input string "abcd") the longest match is returned. As a side effect, the given field of cal is set to the index of the best match, if there is one.

Parameters
text String: the time text being parsed.

start int: where to start parsing.

field int: the date field being parsed.

data String: the string array to parsed.

Returns
int the new start position if matching succeeded; a negative number indicating matching failure, otherwise. As a side effect, sets the cal field field to the index of the best match, if matching succeeded.

patternCharToDateFormatField

Added in API level 24
protected DateFormat.Field patternCharToDateFormatField (char ch)

Returns a DateFormat.Field constant associated with the specified format pattern character.

Parameters
ch char: The pattern character

Returns
DateFormat.Field DateFormat.Field associated with the pattern character

subFormat

Added in API level 24
protected String subFormat (char ch, 
                int count, 
                int beginOffset, 
                FieldPosition pos, 
                DateFormatSymbols fmtData, 
                Calendar cal)

Formats a single field, given its pattern character. Subclasses may override this method in order to modify or add formatting capabilities.

Parameters
ch char: the pattern character

count int: the number of times ch is repeated in the pattern

beginOffset int: the offset of the output string at the start of this field; used to set pos when appropriate

pos FieldPosition: receives the position of a field, when appropriate

fmtData DateFormatSymbols: the symbols for this formatter

cal Calendar

Returns
String

Throws
IllegalArgumentException

subParse

Added in API level 24
protected int subParse (String text, 
                int start, 
                char ch, 
                int count, 
                boolean obeyCount, 
                boolean allowNegative, 
                boolean[] ambiguousYear, 
                Calendar cal)

Protected method that converts one field of the input string into a numeric field value in cal. Returns -start (for ParsePosition) if failed. Subclasses may override this method to modify or add parsing capabilities.

Parameters
text String: the time text to be parsed.

start int: where to start parsing.

ch char: the pattern character for the date field text to be parsed.

count int: the count of a pattern character.

obeyCount boolean: if true, then the next field directly abuts this one, and we should use the count to know when to stop parsing.

allowNegative boolean

ambiguousYear boolean: return parameter; upon return, if ambiguousYear[0] is true, then a two-digit year was parsed and may need to be readjusted.

Returns
int the new start position if matching succeeded; a negative number indicating matching failure, otherwise. As a side effect, set the appropriate field of cal with the parsed value.

zeroPaddingNumber

Added in API level 24
protected String zeroPaddingNumber (long value, 
                int minDigits, 
                int maxDigits)

Formats a number with the specified minimum and maximum number of digits.

Parameters
value long

minDigits int

maxDigits int

Returns
String