Formats a Date into a date/time string. This method simply calls the java.text.SimpleDateFormat.format(Date)} method,
see the complete Javadoc for this method for further details.
Here is a summary of the formatting pattern characters that can be used:
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
{@link 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 {@code 'Y'} is specified and the calendar doesn't support any week
years, the calendar year ({@code 'y'}) is used instead. The
support of week years can be tested with a call to
DateFormat.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:GMTSignHours:MinutesSign: one of
+ -Hours:DigitDigitDigitMinutes:DigitDigitDigit: 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 formatting, if the offset value from GMT is 0, {@code "Z"} is
produced. If the number of pattern letters is 1, any fraction of an hour
is ignored. For example, if the pattern is {@code "X"} and the time zone is
{@code "GMT+05:30"}, {@code "+05"} is produced.
For parsing, {@code "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, {@link IllegalArgumentException} is thrown when constructing a {@code
SimpleDateFormat} or applying a pattern.
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.
Here is a summary of the formatting pattern characters that can be used:
G
AD
y
1996
;96
Y
2009
;09
M
July
;Jul
;07
w
27
W
2
D
189
d
10
F
2
E
Tuesday
;Tue
u
1
a
PM
H
0
k
24
K
0
h
12
m
30
s
55
S
978
z
Pacific Standard Time
;PST
;GMT-08:00
Z
-0800
X
-08
;-0800
;-08:00
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 theSimpleDateFormat
instance is created. For example, using a pattern of "MM/dd/yy" and aSimpleDateFormat
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 {@link 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.If week year {@code 'Y'} is specified and the calendar doesn't support any week years, the calendar year ({@code 'y'}) is used instead. The support of week years can be tested with a call to DateFormat.getCalendar().isWeekDateSupported().
For parsing, RFC 822 time zones are also accepted.
For parsing, general time zones are also accepted.
For formatting, if the offset value from GMT is 0, {@code "Z"} is produced. If the number of pattern letters is 1, any fraction of an hour is ignored. For example, if the pattern is {@code "X"} and the time zone is {@code "GMT+05:30"}, {@code "+05"} is produced.
For parsing, {@code "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, {@link IllegalArgumentException} is thrown when constructing a {@code SimpleDateFormat} or applying a pattern.