DATE_FORMAT

The DATE_FORMAT command assigns a format template to the definition of an object that has a DATETIME, TIMESTAMP, TIMESTAMP_TZ, TIMESTAMP_LTZ, DSINTERVAL, or YMINTERVAL data type.

The datetime format template is a template that describes the format of datetime data stored in a character string. The template does not change the internal representation of the value in the Database. When you convert a character string into a date, the template determines how Oracle OLAP interprets the string.

In order to assign a datetime format template to a definition, the definition must be the one most recently defined or considered during the current session. When it is not, you must first use a CONSIDER statement to make it the current definition.

Syntax

DATE_FORMAT [datetime_format_template]

Arguments

datetime_format_template

An expression composed of one or more datetime format elements that specifies the format for entering and displaying the values of the current object. See Table 9-4, "Datetime Format Elements" for the elements that you can specify in the template. Keep the following points in mind when creating a template:

• The total length of a datetime format template cannot exceed 22 characters

• For input format models, format items cannot appear twice, and format items that represent similar information cannot be combined. For example, you cannot use 'SYYYY' and 'BC' in the same format string.

• Some of the datetime format elements cannot be used in the TO_* datetime functions, as noted in Table 2-7, "Datetime Fields and Values".

• The following datetime format elements can be used in timestamp and interval format models, but not in the original DATETIME format model: FF, TZD, TZH, TZM, and TZR.

• Many datetime format elements are blank padded to a specific length.

When template is omitted, any existing date format template for the current definition is deleted and the default datetime format template is used. (See "Default Datetime Format Template", for a discussion of the default datetime format template.)

Table 9-4 Datetime Format Elements

Element	Specify in TO_* datetime functions?	Description
- / , . ; : "text"	Yes	Punctuation and quoted text is reproduced in the result.
AD A.D.	Yes	AD indicator with or without periods.
AM A.M.	Yes	Meridian indicator with or without periods.
BC B.C.	Yes	BC indicator with or without periods.
CC SCC	No	Century. If the last 2 digits of a 4-digit year are between 01 and 99 (inclusive), then the century is one greater than the first 2 digits of that year. If the last 2 digits of a 4-digit year are 00, then the century is the same as the first 2 digits of that year. For example, 2002 returns 21; 2000 returns 20.
D	Yes	Day of week (1-7).
DAY	Yes	Name of day, padded with blanks to display width of the widest name of day in the date language used for this element.
DD	Yes	Day of month (1-31).
DDD	Yes	Day of year (1-366).
DL	Yes	Returns a value in the long date format, which is an extension of Oracle Database's DATETIME format (the current value of the NLS_DATE_FORMAT parameter). Makes the appearance of the date components (day name, month number, and so forth) depend on the NLS_TERRITORY and NLS_LANGUAGE parameters. For example, in the AMERICAN_AMERICA locale, this is equivalent to specifying the format 'fmDay, Month dd, yyyy'. In the GERMAN_GERMANY locale, it is equivalent to specifying the format'fmDay, dd. Month yyyy'. Restriction: You can specify this format only with the TS element, separated by white space.
DS	Yes	Returns a value in the short date format. Makes the appearance of the date components (day name, month number, and so forth) depend on the NLS_TERRITORY and NLS_LANGUAGE parameters. For example, in the AMERICAN_AMERICA locale, this is equivalent to specifying the format 'MM/DD/RRRR'. In the ENGLISH_UNITED_KINGDOM locale, it is equivalent to specifying the format 'DD/MM/RRRR'. Restriction: You can specify this format only with the TS element, separated by white space.
DY	Yes	Abbreviated name of day.
E	No	Abbreviated era name (Japanese Imperial, ROC Official, and Thai Buddha calendars).
EE	No	Full era name (Japanese Imperial, ROC Official, and Thai Buddha calendars).
FF [1..9]	Yes	Fractional seconds; no radix character is printed (use the X format element to add the radix character). Use the numbers 1 to 9 after FF to specify the number of digits in the fractional second portion of the datetime value returned. If you do not specify a digit, then Oracle Database uses the precision specified for the datetime data type or the data type's default precision. Examples: 'HH:MI:SS.FF' SELECT TO_CHAR(SYSTIMESTAMP, 'SS.FF3') from dual;
FM	Yes	Returns a value with no leading or trailing blanks. See Also: Additional discussion on this format model modifier in the Oracle Database SQL Language Reference
FX	Yes	Requires exact matching between the character data and the format model. See Also: Additional discussion on this format model modifier in the Oracle Database SQL Language Reference
HH	Yes	Hour of day (1-12).
HH12	No	Hour of day (1-12).
HH24	Yes	Hour of day (0-23).
IW	No	Week of year (1-52 or 1-53) based on the ISO standard.
IYY IY I	No	Last 3, 2, or 1 digit(s) of ISO year.
IYYY	No	4-digit year based on the ISO standard.
J	Yes	Julian day; the number of days since January 1, 4712 BC. Number specified with J must be integers.
MI	Yes	Minute (0-59).
MM	Yes	Month (01-12; January = 01).
MON	Yes	Abbreviated name of month.
MONTH	Yes	Name of month, padded with blanks to display width of the widest name of month in the date language used for this element.
PM P.M.	No	Meridian indicator with or without periods.
Q	No	Quarter of year (1, 2, 3, 4; January - March = 1).
RM	Yes	Roman numeral month (I-XII; January = I).
RR	Yes	Lets you store 20th century dates in the 21st century using only two digits. See Also: Additional discussion on RR datetime format element in the Oracle Database SQL Language Reference
RRRR	Yes	Round year. Accepts either 4-digit or 2-digit input. If 2-digit, provides the same return as RR. If you do not want this functionality, then enter the 4-digit year.
SS	Yes	Second (0-59).
SSSSS	Yes	Seconds past midnight (0-86399).
TS	Yes	Returns a value in the short time format. Makes the appearance of the time components (hour, minutes, and so forth) depend on the NLS_TERRITORY and NLS_LANGUAGE initialization parameters. Restriction: You can specify this format only with the DL or DS element, separated by white space.
TZD	Yes	Daylight savings information. The TZD value is an abbreviated time zone string with daylight savings information. It must correspond with the region specified in TZR. Example: PST (for US/Pacific standard time); PDT (for US/Pacific daylight time).
TZH	Yes	Time zone hour. (See TZM format element.) Example: 'HH:MI:SS.FFTZH:TZM'.
TZM	Yes	Time zone minute. (See TZH format element.) Example: 'HH:MI:SS.FFTZH:TZM'.
TZR	Yes	Time zone region information. The value must be one of the time zone regions supported in the Database. Example: US/Pacific
WW	No	Week of year (1-53) where week 1 starts on the first day of the year and continues to the seventh day of the year.
W	No	Week of month (1-5) where week 1 starts on the first day of the month and ends on the seventh.
X	Yes	Local radix character. Example: 'HH:MI:SSXFF'.
Y,YYY	Yes	Year with comma in this position.
YEAR SYEAR	No	Year, spelled out; S prefixes BC dates with a minus sign (-).
YYYY SYYYY	Yes	4-digit year; S prefixes BC dates with a minus sign.
YYY YY Y	Yes	Last 3, 2, or 1 digit(s) of year.

Notes

Default Datetime Format Template

The default datetime format template is specified either explicitly with the initialization parameter NLS_DATE_FORMAT or implicitly with the initialization parameter NLS_TERRITORY. You can change the default datetime formats for your session with the ALTER SESSION statement.

ISO Standard Date Format Elements

Oracle calculates the values returned by the datetime format elements IYYY, IYY, IY, I, and IW according to the ISO standard. For information on the differences between these values and those returned by the datetime format elements YYYY, YYY, YY, Y, and WW, see the discussion of globalization support in Oracle Database Globalization Support Guide.

The RR Datetime Format Element

The RR datetime format element is similar to the YY datetime format element, but it provides additional flexibility for storing date values in other centuries. The RR datetime format element lets you store 20th century dates in the 21st century by specifying only the last two digits of the year.

If you use the TO_DATE function with the YY datetime format element, then the year returned always has the same first 2 digits as the current year. If you use the RR datetime format element instead, then the century of the return value varies according to the specified two-digit year and the last two digits of the current year.

That is:

• If the specified two-digit year is 00 to 49, then

  • If the last two digits of the current year are 00 to 49, then the returned year has the same first two digits as the current year.

  • If the last two digits of the current year are 50 to 99, then the first 2 digits of the returned year are 1 greater than the first 2 digits of the current year.

• If the specified two-digit year is 50 to 99, then

  • If the last two digits of the current year are 00 to 49, then the first 2 digits of the returned year are 1 less than the first 2 digits of the current year.

  • If the last two digits of the current year are 50 to 99, then the returned year has the same first two digits as the current year.

Datetime Format Element Suffixes

Table 9-5, "Date Format Element Suffixes" lists suffixes that can be added to datetime format elements:

Keep the following in mind when using date format element suffixes:

• When you add one of these suffixes to a datetime format element, the return value is always in English.

• Datetime suffixes are valid only to format output. You cannot use them to insert a date into the Database.

Datetime Format Elements and Globalization Support

The functionality of some datetime format elements depends on the country and language in which you are using Oracle Database. For example, these datetime format elements return spelled values:

• MONTH

• MON

• DAY

• DY

• BC or AD or B.C. or A.D.

• AM or PM or A.M or P.M.

The language in which these values are returned is specified either explicitly with the initialization parameter NLS_DATE_LANGUAGE or implicitly with the initialization parameter NLS_LANGUAGE. The values returned by the YEAR and SYEAR datetime format elements are always in English.

The datetime format element D returns the number of the day of the week (1-7). The day of the week that is numbered 1 is specified implicitly by the initialization parameter NLS_TERRITORY.

Uppercase Letters in Date Format Elements

Capitalization in a spelled-out word, abbreviation, or Roman numeral follows capitalization in the corresponding format element. For example, the datetime format template 'DAY' produces capitalized words like 'MONDAY'; 'Day' produces 'Monday'; and 'day' produces 'monday'.

Punctuation and Character Literals in Datetime Format Templates

You can include these characters in a datetime format template:

• Punctuation such as hyphens, slashes, commas, periods, and colons

• Character literals, enclosed in double quotation marks

These characters appear in the return value in the same location as they appear in the format model.

Oracle returns an error if an alphanumeric character is found in the date string where a punctuation character is found in the format string. For example, the following format string returns an error:

TO_CHAR (TO_DATE('0297','MM/YY'), 'MM/YY')

Examples

SHOW NLS_DATE_FORMAT
DD-MON-RR

DEFINE mydatetime VARIABLE DATETIME
mydatetime = CURRENT_TIMESTAMP
 

REPORT mydatetime

MYDATETIME
-----------
02-FEB-07
 

CONSIDER mydatetime
DATE_FORMAT MON-RRRR-DD-HH24
 

REPORT mydatetime

MYDATETIME
--------------
FEB-2007-02-10