SimpleDateFormat

class U_I18N_API SimpleDateFormat : public DateFormat

SimpleDateFormat is a concrete class for formatting and parsing dates in a language-independent manner

Inheritance:

Public Fields
static const UnicodeString fgErasTag: Resource bundle file suffix and tag names used by this class
static const UDate fgSystemDefaultCentury: If a start date is set to this value, that indicates that the system default start is in effect for this instance

Public Methods
SimpleDateFormat(UErrorCode& status): Construct a SimpleDateFormat using the default pattern for the default locale
SimpleDateFormat(const UnicodeString& pattern, UErrorCode& status): Construct a SimpleDateFormat using the given pattern and the default locale
SimpleDateFormat(const UnicodeString& pattern, const Locale& locale, UErrorCode& status): Construct a SimpleDateFormat using the given pattern and locale
SimpleDateFormat(const UnicodeString& pattern, DateFormatSymbols* formatDataToAdopt, UErrorCode& status): Construct a SimpleDateFormat using the given pattern and locale-specific symbol data
SimpleDateFormat(const UnicodeString& pattern, const DateFormatSymbols& formatData, UErrorCode& status): Construct a SimpleDateFormat using the given pattern and locale-specific symbol data
SimpleDateFormat(const SimpleDateFormat&): Copy constructor
SimpleDateFormat& operator=(const SimpleDateFormat&): Assignment operator
virtual ~SimpleDateFormat(): Destructor
virtual Format* clone(void) const: Clone this Format object polymorphically
virtual bool_t operator==(const Format& other) const: Return true if the given Format objects are semantically equal
virtual UnicodeString& format( UDate date, UnicodeString& toAppendTo, FieldPosition& pos) const: Format a date or time, which is the standard millis since 24:00 GMT, Jan 1, 1970
virtual UnicodeString& format( const Formattable& obj, UnicodeString& toAppendTo, FieldPosition& pos, UErrorCode& status) const: Format a date or time, which is the standard millis since 24:00 GMT, Jan 1, 1970
UnicodeString& format(const Formattable& obj, UnicodeString& result, UErrorCode& status) const: Redeclared DateFormat method
UnicodeString& format(UDate date, UnicodeString& result) const: Redeclared DateFormat method
virtual UDate parse( const UnicodeString& text, ParsePosition& pos) const: Parse a date/time string starting at the given parse position
virtual UDate parse( const UnicodeString& text, UErrorCode& status) const: Parse a date/time string
virtual void set2DigitYearStart(UDate d, UErrorCode& status): Set the start UDate used to interpret two-digit year strings
UDate get2DigitYearStart(UErrorCode& status) const: Get the start UDate used to interpret two-digit year strings
virtual UnicodeString& toPattern(UnicodeString& result) const: Return a pattern string describing this date format
virtual UnicodeString& toLocalizedPattern(UnicodeString& result, UErrorCode& status) const: Return a localized pattern string describing this date format
virtual void applyPattern(const UnicodeString& pattern): Apply the given unlocalized pattern string to this date format
virtual void applyLocalizedPattern(const UnicodeString& pattern, UErrorCode& status): Apply the given localized pattern string to this date format
virtual const DateFormatSymbols* getDateFormatSymbols(void) const: Gets the date/time formatting symbols (this is an object carrying the various strings and other symbols used in formatting: e
virtual void adoptDateFormatSymbols(DateFormatSymbols* newFormatSymbols): Set the date/time formatting symbols
virtual void setDateFormatSymbols(const DateFormatSymbols& newFormatSymbols): Set the date/time formatting data
static UClassID getStaticClassID(void): Return the class ID for this class
virtual UClassID getDynamicClassID(void) const: Returns a unique class ID POLYMORPHICALLY
static void translatePattern(const UnicodeString& originalPattern, UnicodeString& translatedPattern, const UnicodeString& from, const UnicodeString& to, UErrorCode& status): Translate a pattern, mapping each character in the from string to the corresponding character in the to string
void parseAmbiguousDatesAsAfter(UDate startDate, UErrorCode& status): Sets the starting date of the 100-year window that dates with 2-digit years are considered to fall within

Inherited from DateFormat:

Public Classes
enum EField

ERA_FIELD
These constants are provided for backwards compatibility only, and are deprecated
enum EStyle

FULL
These constants are provided for backwards compatibility only, and are deprecated

Public Methods
virtual void parseObject(const UnicodeString& source, Formattable& result, ParsePosition& parse_pos) const
static DateFormat* createInstance(void)
static DateFormat* createTimeInstance(EStyle style = kDefault, const Locale& aLocale = Locale::getDefault())
static DateFormat* createDateInstance(EStyle style = kDefault, const Locale& aLocale = Locale::getDefault())
static DateFormat* createDateTimeInstance(EStyle dateStyle = kDefault, EStyle timeStyle = kDefault, const Locale& aLocale = Locale::getDefault())
static const Locale* getAvailableLocales(int32_t& count)
virtual bool_t isLenient(void) const
virtual void setLenient(bool_t lenient)
virtual const Calendar* getCalendar(void) const
virtual void adoptCalendar(Calendar* calendarToAdopt)
virtual void setCalendar(const Calendar& newCalendar)
virtual const NumberFormat* getNumberFormat(void) const
virtual void adoptNumberFormat(NumberFormat* formatToAdopt)
virtual void setNumberFormat(const NumberFormat& newNumberFormat)
virtual const TimeZone& getTimeZone(void) const
virtual void adoptTimeZone(TimeZone* zoneToAdopt)
virtual void setTimeZone(const TimeZone& zone)

Protected Fields
Calendar* fCalendar
NumberFormat* fNumberFormat

Inherited from Format:

Public Methods
bool_t operator!=(const Format& other) const

Documentation

SimpleDateFormat is a concrete class for formatting and parsing dates in a language-independent manner. It allows for formatting (millis -> text), parsing (text -> millis), and normalization. Formats/Parses a date or time, which is the standard milliseconds since 24:00 GMT, Jan 1, 1970.
Clients are encouraged to create a date-time formatter using DateFormat::getInstance(), getDateInstance(), getDateInstance(), or 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. 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().
Date/Time format syntax:
The date/time format is specified by means of a string time pattern. In this pattern, all ASCII letters are reserved as pattern letters, which are defined as the following:
.   Symbol   Meaning                 Presentation       Example
.   ------   -------                 ------------       -------
.   G        era designator          (Text)             AD
.   y        year                    (Number)           1996
.   M        month in year           (Text & Number)    July & 07
.   d        day in month            (Number)           10
.   h        hour in am/pm (1~12)    (Number)           12
.   H        hour in day (0~23)      (Number)           0
.   m        minute in hour          (Number)           30
.   s        second in minute        (Number)           55
.   S        millisecond             (Number)           978
.   E        day in week             (Text)             Tuesday
.   D        day in year             (Number)           189
.   F        day of week in month    (Number)           2 (2nd Wed in July)
.   w        week in year            (Number)           27
.   W        week in month           (Number)           2
.   a        am/pm marker            (Text)             PM
.   k        hour in day (1~24)      (Number)           24
.   K        hour in am/pm (0~11)    (Number)           0
.   z        time zone               (Text)             Pacific Standard Time
.   '        escape for text
.   ''       single quote                               '
The count of pattern letters determine the format.
(Text): 4 or more, use full form, <4, use short or abbreviated form if it exists. (e.g., "EEEE" produces "Monday", "EEE" produces "Mon")
(Number): the minimum number of digits. Shorter numbers are zero-padded to this amount (e.g. if "m" produces "6", "mm" produces "06"). Year is handled specially; that is, if the count of 'y' is 2, the Year will be truncated to 2 digits. (e.g., if "yyyy" produces "1997", "yy" produces "97".)
(Text & Number): 3 or over, use text, otherwise use number. (e.g., "M" produces "1", "MM" produces "01", "MMM" produces "Jan", and "MMMM" produces "January".)
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 failing UErrorCode result during formatting or parsing.
Examples using the US locale:
.   Format Pattern                         Result
.   --------------                         -------
.   "yyyy.MM.dd G 'at' HH:mm:ss z"    ->>  1996.07.10 AD at 15:08:56 PDT
.   "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, z"                       ->>  0:00 PM, PST
.   "yyyyy.MMMMM.dd GGG hh:mm aaa"    ->>  1996.July.10 AD 12:08 PM
Code Sample:
.    UErrorCode success = U_ZERO_ERROR;
.    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", success );
.    GregorianCalendar cal(success);
.    UDate currentTime_1 = cal.getTime(success);
.    FieldPosition fp(0);
.    UnicodeString dateString;
.    formatter->format( currentTime_1, dateString, fp );
.    cout << "result: " << dateString << endl;
.    
.    // Parse the previous string back into a Date.
.    ParsePosition pp(0);
.    UDate currentTime_2 = formatter->parse(dateString, pp );
In the above 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 ("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 Unicode::isDigit(), 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 has more than 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.
For time zones that have no names, SimpleDateFormat uses 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 timezone. There is one common number format to handle all the numbers; the digit count is handled programmatically according to the pattern.

SimpleDateFormat(UErrorCode& status)

Construct a SimpleDateFormat using the default pattern for the default locale.

[Note:] Not all locales support SimpleDateFormat; for full generality, use the factory methods in the DateFormat class.

SimpleDateFormat(const UnicodeString& pattern, UErrorCode& status)

Construct a SimpleDateFormat using the given pattern and the default locale. The locale is used to obtain the symbols used in formatting (e.g., the names of the months), but not to provide the pattern.

[Note:] Not all locales support SimpleDateFormat; for full generality, use the factory methods in the DateFormat class.

SimpleDateFormat(const UnicodeString& pattern, const Locale& locale, UErrorCode& status)

Construct a SimpleDateFormat using the given pattern and locale. The locale is used to obtain the symbols used in formatting (e.g., the names of the months), but not to provide the pattern.

[Note:] Not all locales support SimpleDateFormat; for full generality, use the factory methods in the DateFormat class.

SimpleDateFormat(const UnicodeString& pattern, DateFormatSymbols* formatDataToAdopt, UErrorCode& status)

Construct a SimpleDateFormat using the given pattern and locale-specific symbol data. The formatter takes ownership of the DateFormatSymbols object; the caller is no longer responsible for deleting it.

SimpleDateFormat(const UnicodeString& pattern, const DateFormatSymbols& formatData, UErrorCode& status)

Construct a SimpleDateFormat using the given pattern and locale-specific symbol data. The DateFormatSymbols object is NOT adopted; the caller remains responsible for deleting it.

SimpleDateFormat(const SimpleDateFormat&)

Copy constructor

SimpleDateFormat& operator=(const SimpleDateFormat&)

Assignment operator

virtual ~SimpleDateFormat()

Destructor

virtual Format* clone(void) const

Clone this Format object polymorphically. The caller owns the result and should delete it when done.

virtual bool_t operator==(const Format& other) const

Return true if the given Format objects are semantically equal. Objects of different subclasses are considered unequal.

virtual UnicodeString& format( UDate date, UnicodeString& toAppendTo, FieldPosition& pos) const

Format a date or time, which is the standard millis since 24:00 GMT, Jan 1, 1970. Overrides DateFormat pure virtual method.

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

Returns:: A reference to 'toAppendTo'.
Parameters:: date - The date-time value to be formatted into a date-time string.
toAppendTo - The result of the formatting operation is appended to this string.
pos - The formatting position. On input: an alignment field, if desired. On output: the offsets of the alignment field.

virtual UnicodeString& format( const Formattable& obj, UnicodeString& toAppendTo, FieldPosition& pos, UErrorCode& status) const

Format a date or time, which is the standard millis since 24:00 GMT, Jan 1, 1970. Overrides DateFormat pure virtual method.

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

Returns:: A reference to 'toAppendTo'.
Parameters:: obj - A Formattable containing the date-time value to be formatted into a date-time string. If the type of the Formattable is a numeric type, it is treated as if it were an instance of Date.
toAppendTo - The result of the formatting operation is appended to this string.
pos - The formatting position. On input: an alignment field, if desired. On output: the offsets of the alignment field.

UnicodeString& format(const Formattable& obj, UnicodeString& result, UErrorCode& status) const

Redeclared DateFormat method

UnicodeString& format(UDate date, UnicodeString& result) const

Redeclared DateFormat method

virtual UDate parse( const UnicodeString& text, ParsePosition& pos) const

Parse a date/time string starting at the given parse position. For example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date that is equivalent to Date(837039928046).

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

Returns:: A valid UDate if the input could be parsed.
Parameters:: text - The date/time string to be parsed
pos - 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:: DateFormat::setLenient(boolean)

virtual UDate parse( const UnicodeString& text, UErrorCode& status) const

Parse a date/time string. For example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a UDate that is equivalent to Date(837039928046). Parsing begins at the beginning of the string and proceeds as far as possible. Assuming no parse errors were encountered, this function doesn't return any information about how much of the string was consumed by the parsing. If you need that information, use the version of parse() that takes a ParsePosition.

Returns:: A valid UDate if the input could be parsed.
Parameters:: text - The date/time string to be parsed
status - Filled in with U_ZERO_ERROR if the parse was successful, and with an error value if there was a parse error.

virtual void set2DigitYearStart(UDate d, UErrorCode& status)

Set the start UDate used to interpret two-digit year strings. When dates are parsed having 2-digit year strings, they are placed within a assumed range of 100 years starting on the two digit start date. For example, the string "24-Jan-17" may be in the year 1817, 1917, 2017, or some other year. SimpleDateFormat chooses a year so that the resultant date is on or after the two digit start date and within 100 years of the two digit start date.

By default, the two digit start date is set to 80 years before the current time at which a SimpleDateFormat object is created.

UDate get2DigitYearStart(UErrorCode& status) const

Get the start UDate used to interpret two-digit year strings. When dates are parsed having 2-digit year strings, they are placed within a assumed range of 100 years starting on the two digit start date. For example, the string "24-Jan-17" may be in the year 1817, 1917, 2017, or some other year. SimpleDateFormat chooses a year so that the resultant date is on or after the two digit start date and within 100 years of the two digit start date.

By default, the two digit start date is set to 80 years before the current time at which a SimpleDateFormat object is created.

virtual UnicodeString& toPattern(UnicodeString& result) const

Return a pattern string describing this date format

virtual UnicodeString& toLocalizedPattern(UnicodeString& result, UErrorCode& status) const

Return a localized pattern string describing this date format. In most cases, this will return the same thing as toPattern(), but a locale can specify characters to use in pattern descriptions in place of the ones described in this class's class documentation. (Presumably, letters that would be more mnemonic in that locale's language.) This function would produce a pattern using those letters.

Parameters:: result - Receives the localized pattern.
status - Output param set to success/failure code on exit. If the pattern is invalid, this will be set to a failure result.

virtual void applyPattern(const UnicodeString& pattern)

Apply the given unlocalized pattern string to this date format. (i.e., after this call, this formatter will format dates according to the new pattern)

Parameters:: pattern - The pattern to be applied.

virtual void applyLocalizedPattern(const UnicodeString& pattern, UErrorCode& status)

Apply the given localized pattern string to this date format. (see toLocalizedPattern() for more information on localized patterns.)

Parameters:: pattern - The localized pattern to be applied.
status - Output param set to success/failure code on exit. If the pattern is invalid, this will be set to a failure result.

virtual const DateFormatSymbols* getDateFormatSymbols(void) const

Gets the date/time formatting symbols (this is an object carrying the various strings and other symbols used in formatting: e.g., month names and abbreviations, time zone names, AM/PM strings, etc.)

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

virtual void adoptDateFormatSymbols(DateFormatSymbols* newFormatSymbols)

Set the date/time formatting symbols. The caller no longer owns the DateFormatSymbols object and should not delete it after making this call.

Parameters:: newFormatData - the given date-time formatting data.

virtual void setDateFormatSymbols(const DateFormatSymbols& newFormatSymbols)

Set the date/time formatting data

Parameters:: newFormatData - the given date-time formatting data.

static const UnicodeString fgErasTag

Resource bundle file suffix and tag names used by this class

static UClassID getStaticClassID(void)

Return the class ID for this class. This is useful only for comparing to a return value from getDynamicClassID(). For example:

.   Base* polymorphic_pointer = createPolymorphicObject();
.   if (polymorphic_pointer->getDynamicClassID() ==
.       erived::getStaticClassID()) ...

Returns:: The class ID for all objects of this class.

virtual UClassID getDynamicClassID(void) const

Returns a unique class ID POLYMORPHICALLY. Pure virtual override. This method is to implement a simple version of RTTI, since not all C++ compilers support genuine RTTI. Polymorphic operator==() and clone() methods call this method.

Returns:: The class ID for this object. All objects of a given class have the same class ID. Objects of other classes have different class IDs.

static void translatePattern(const UnicodeString& originalPattern, UnicodeString& translatedPattern, const UnicodeString& from, const UnicodeString& to, UErrorCode& status)

Translate a pattern, mapping each character in the from string to the corresponding character in the to string. Return an error if the original pattern contains an unmapped character, or if a quote is unmatched. Quoted (single quotes only) material is not translated.

void parseAmbiguousDatesAsAfter(UDate startDate, UErrorCode& status)