This section describes how to use Java date/time patterns for parsing and formatting times and dates. See http://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html for more detail.
You specify date and time formats using pattern letters. Date and time pattern strings use unquoted letters from ‘A’ to ‘Z’ and from ‘a’ to ‘z’, with each letter representing a formatting element.
Note: if you include other characters, they will be incorporated into the output string during formatting or compared to 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 |
---|---|---|---|
y | Year | Year | yyyy; yy 2018;18 |
Y | Week year | Year | YYYY; YY 2009; 09 |
M | Month in year | Month | MMMM; MMM; MM July; Jul; 07 |
w | Week in year | Number | ww; 27 |
W | Week in month | Number | W 2 |
D | Day in year | Number | DDD 321 |
d | Day in month | Number | dd 10 |
F | Day of week in month | Number | F 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 |
You determine the exact presentation by repeating pattern letters, along the lines of YYYY. Pattern letters are usually repeated, as their number determines the exact presentation:
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.
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.
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”), the formatting codes and rules are the same as for the SimpleDateFormat java class: the abbreviated year is interpreted relative to some century 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, 2018, 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 ch), 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 number of pattern letters is 3 or more, the month is interpreted as text. Otherwise, it is interpreted as a number.
Time zones are interpreted as text if they have names. For time zones representing a GMT offset value, the following syntax is used:
<GMTOffsetTimeZone>: <sign> <hours> ':' <minutes>
<sign>: + | -
<hours>: <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.
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.
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.
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 | Notes |
---|---|---|
‘yyyy.MM.dd G ‘‘at’’ HH:mm:ss z’ | 2001.07.04 AD at 12:08:56 PDT | The single quotes around the word at have to be doubled up as they are within a SQL character literal |
‘EEE, MMM d, ‘‘yy’ | Wed, Jul 4, ‘01 | |
‘h:mm a’ | 12:08 PM | |
‘h ‘‘o'‘‘‘clock’’ a, zzzz’ | 12 o’clock PM, Pacific Daylight Time | The literal o’clock has to be surrounded by a pair of double quotes. The apostrophe within o’clock has to be doubled once (because it is within a string literal in the date format) and again (because the date format is itself within a SQL character literal) - so there must be a sequence of 4 single quote characters. Using a single letter for hour means we don’t generate times like 02 o’clock; using h means we get the 12 hour clock. |
‘K:mm a, z’ | 0:08 PM, PDT | |
‘yyyyy.MMMMM.dd GGG hh:mm aaa’ | 02001.July.04 AD 12:08 PM | a format containing a sequence of 5 y characters generates a 5 digit year. |
‘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 | This ISO-8601 format has an embedded ‘T’ - the single quotes within the SQL character literal must be doubled up. The -0700 represents a time zone (it could be Pacific Daylight Savings). Normally s-Server runs in the UTC timezone (which would be represented as +0000 in this format). |
The same pattern letters shown at first, above, in Date or Time Component order are shown below in alphabetic order for easy reference.
Pattern Letter | Date or Time Component | Presentation as text or number | Examples |
---|---|---|---|
a | Am/pm marker | Text | PM |
D | Day in year | Number | 189 |
d | Day in month | Number | 10 |
E | Day in week | Text | EE=Tu; EEE=Tue; EEEE=Tuesday |
F | Day of week in month | Number | 2 |
G | Era designator | Text | AD |
H | Hour in day (0-23) | Number | 0 |
h | Hour in am/pm (1-12) | Number | 12 |
k | Hour in day (1-24) | Number | 24 |
K | Hour in am/pm (0-11) | Number | 0 |
M | Month in year | Month | July; Jul; 07 |
m | Minute in hour | Number | 30 |
s | Second in minute | Number | 55 |
S | Millisecond | Number | 978 |
w | Week in year | Number | 27 |
W | Week in month | Number | 2 |
y | Year | Year | 1996; 96 |
z | Time zone | General | Pacific Standard Time; PST; GMT-08:00 | |
Z | Time zone | RFC | -0800 |