Datetime Conversion Functions

You specify date and time formats using patterned 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.

For more information, see Class SimpleDateFormat on the Oracle website.

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 pattern letters in the following table 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	MMM;MM;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.

Text

If the number of repeated 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, 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), 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.