Mega Code Archive
0211 SimpleDateFormat class introduction
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SimpleDateFormat is a concrete class for formatting and parsing dates in a locale-sensitive manner. It allows for formatting date to text, parsing from text to date, and normalization.
Date and Time Patterns
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.
Month:If the number of pattern letters is 3 or more, the month is interpreted as text; otherwise, it is interpreted as a number.
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.
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
RFC 822 time zone: For formatting, the RFC 822 4-digit time zone format is used:
RFC822TimeZone:
Sign TwoDigitHours Minutes
TwoDigitHours:
Digit Digit
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
SimpleDateFormat()
Creates a SimpleDateFormat using the default pattern and date format symbols for the default locale.
SimpleDateFormat(String pattern)
Creates a SimpleDateFormat using the given pattern and the default date format symbols for the default locale.
SimpleDateFormat(String pattern, DateFormatSymbols formatSymbols)
Creates a SimpleDateFormat using the given pattern and date format symbols.
SimpleDateFormat(String pattern, Locale locale)
Creates a SimpleDateFormat using the given pattern and the default date format symbols for the given locale.
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.
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.
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.
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