A date is a three-part value (year, month, and day) designating a point in time under the Gregorian calendar20, which is assumed to have been in effect from the year 1 A.D. The range of the year part is 0001 to 9999. The date formats *JUL, *MDY, *DMY, and *YMD can only represent dates in the range 1940 through 2039. The range of the month part is 1 to 12. The range of the day part is 1 to x, where x is 28, 29, 30, or 31, depending on the month and year.
The internal representation of a date is a string of 4 bytes that contains an integer. The integer (called the Scaliger number) represents the date. The length of a DATE column as described in the SQLDA is 6, 8, or 10 bytes, depending on which format is used. These are the appropriate lengths for string representations for the value.
Date strings
A string representation of a date is a character or a Unicode graphic string that starts with a digit and has a length of at least 6 characters. Trailing blanks can be included. Leading zeros can be omitted from the month and day portions when using the IBM(R) SQL standard formats. Each IBM SQL standard format is identified by name and includes an associated abbreviation (for use by the CHAR function). Other formats do not have an abbreviation to be used by the CHAR function. The separators for two-digit year formats are controlled by the date separator (DATSEP) parameter. Valid string formats for dates are listed in Table below.The database manager recognizes the string as a date when it is either:
- In the format specified by the default date format, or
- In the ANSI/ISO SQL standard date format, or
- In one of the IBM SQL standard date formats, or
- In the unformatted Julian format
| Format Name | Abbreviation | Date Format | Example |
|---|---|---|---|
| ANSI/ISO SQL standard date format (-) | - | DATE 'yyyy-mm-dd' | DATE '1987-10-12' |
| International Standards Organization (*ISO) | ISO | 'yyyy-mm-dd' | '1987-10-12' |
| IBM USA standard (*USA) | USA | 'mm/dd/yyyy' | '10/12/1987' |
| IBM European standard (*EUR) | EUR | 'dd.mm.yyyy' | '12.10.1987' |
| Japanese industrial standard Christian era (*JIS) | JIS | 'yyyy-mm-dd' | '1987-10-12' |
| Unformatted Julian | - | 'yyyyddd' | '1987285' |
| Julian (*JUL) | - | 'yy/ddd' | '87/285' |
| Month, day, year (*MDY) | - | 'mm/dd/yy' | '10/12/87' |
| Day, month, year (*DMY) | - | 'dd/mm/yy' | '12/10/87' |
| Year, month, day (*YMD) | - | 'yy/mm/dd' | '87/12/10' |
The default internal format for date variables is *ISO. This default internal format can be overridden globally by the control specification keyword DATFMT and individually by the definition specification keyword DATFMT.
The hierarchy used when determining the internal date format and separator for a date field is
- From the DATFMT keyword specified on the definition specification
- From the DATFMT keyword specified on the control specification
- *ISO
|
RPG-defined date formats and separators for Date data type
| Format Name | Description | Format (Default Separator) | Valid Separators | Length | Example |
|---|---|---|---|---|---|
| 2-Digit Year Formats | |||||
| *MDY | Month/Day/Year | mm/dd/yy | / - . , '&' | 8 | 01/15/96 |
| *DMY | Day/Month/Year | dd/mm/yy | / - . , '&' | 8 | 15/01/96 |
| *YMD | Year/Month/Day | yy/mm/dd | / - . , '&' | 8 | 96/01/15 |
| *JUL | Julian | yy/ddd | / - . , '&' | 6 | 96/015 |
| 4-Digit Year Formats | |||||
| *ISO | International Standards Organization | yyyy-mm-dd | - | 10 | 1996-01-15 |
| *USA | IBM USA Standard | mm/dd/yyyy | / | 10 | 01/15/1996 |
| *EUR | IBM European Standard | dd.mm.yyyy | . | 10 | 15.01.1996 |
| *JIS | Japanese Industrial Standard Christian Era | yyyy-mm-dd | - | 10 | 1996-01-15 |
Table below lists the *LOVAL, *HIVAL, and default values for all the RPG-defined date formats.
Date Values
| Format name | Description | *LOVAL | *HIVAL | Default Value |
|---|---|---|---|---|
| 2-Digit Year Formats | ||||
| *MDY | Month/Day/Year | 01/01/40 | 12/31/39 | 01/01/40 |
| *DMY | Day/Month/Year | 01/01/40 | 31/12/39 | 01/01/40 |
| *YMD | Year/Month/Day | 40/01/01 | 39/12/31 | 40/01/01 |
| *JUL | Julian | 40/001 | 39/365 | 40/001 |
| 4-Digit Year Formats | ||||
| *ISO | International Standards Organization | 0001-01-01 | 9999-12-31 | 0001-01-01 |
| *USA | IBM USA Standard | 01/01/0001 | 12/31/9999 | 01/01/0001 |
| *EUR | IBM European Standard | 01.01.0001 | 31.12.9999 | 01.01.0001 |
| *JIS | Japanese Industrial Standard Christian Era | 0001-01-01 | 9999-12-31 | 0001-01-01 |
Source: IBM Information center
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