DT Functions: Converting an Integer to a Date

How to:

Available Languages: reporting, Maintain

xThe DT functions convert an integer representing the number of days elapsed since December 31, 1899 to the corresponding date. They are useful when you are performing arithmetic on a date converted to the number of days (for more information, see DA Functions: Converting a Legacy Date to an Integer). The DT functions convert the result back to a date.

There are six DT functions; each one converts a number into a date of a different format.

Note: When USERFNS is set to LOCAL, DT functions only display a six-digit date.

Syntax: How to Convert an Integer to a Date 

function(number, output)

where:

function

Is one of the following:

DTDMY converts a number to a day-month-year date.

DTDYM converts a number to a day-year-month date.

DTMDY converts a number to a month-day-year date.

DTMYD converts a number to a month-year-day date.

DTYDM converts a number to a year-day-month date.

DTYMD converts a number to a year-month-day date.

number

Integer

Is the number of days since December 31, 1899. The number is truncated to an integer.

output

I8xxx, where xxx corresponds to the function DTxxx in the above list.

Is the name of the field containing the result or the format of the output value enclosed in single quotation marks. The output format depends on the function being used.

Example: Converting an Integer to a Date

DTMDY converts the NEWF field (which was converted to the number of days by DAYMD) to the corresponding date and stores the result in NEW_HIRE_DATE: 

-* THIS PROCEDURE CONVERTS HIRE_DATE, WHICH IS IN I6YMD FORMAT,
-* TO A DATE IN I8MDYY FORMAT.
-* FIRST IT USES THE DAYMD FUNCTION TO CONVERT HIRE_DATE 
-* TO A NUMBER OF DAYS.
-* THEN IT USES THE DTMDY FUNCTION TO CONVERT THIS NUMBER OF
-* DAYS TO I8MDYY FORMAT
-*
DEFINE FILE EMPLOYEE
NEWF/I8 WITH EMP_ID = DAYMD(HIRE_DATE, NEWF);
NEW_HIRE_DATE/I8MDYY WITH EMP_ID = DTMDY(NEWF, NEW_HIRE_DATE);
END
TABLE FILE EMPLOYEE
PRINT HIRE_DATE NEW_HIRE_DATE
BY FN BY LN
WHERE DEPARTMENT EQ 'MIS'
END

The output is:

FIRST_NAME  LAST_NAME        HIRE_DATE  NEW_HIRE_DATE
----------  ---------        ---------  -------------
BARBARA     CROSS             81/11/02     11/02/1981
DIANE       JONES             82/05/01     05/01/1982
JOHN        MCCOY             81/07/01     07/01/1981
MARY        GREENSPAN         82/04/01     04/01/1982
            SMITH             81/07/01     07/01/1981
ROSEMARIE   BLACKWOOD         82/04/01     04/01/1982