Date/time functions

The date/time functions do the following:

• DATE, TIME, and TIMESTAMP change the data type of their argument to the associated date/time data type.
• CHAR changes the data type of its argument (a DATE or TIME value) to the CHAR data type.
• DAYS calculates the number of days between one date and another.
• YEAR, MONTH, DAY, HOUR, MINUTE, SECOND, and MICROSECOND select parts of DATE, TIME or TIMESTAMP values.

Each date/time function is followed by an argument enclosed in parentheses. The following example lists the projects, by number, of each project scheduled to begin in 1990. It does this by applying the YEAR date/time function to the STARTD column of the Q.PROJECT table.

This query:

SELECT PROJNO, STARTD, ENDD, TIMESTAMP
FROM Q.PROJECT
WHERE YEAR(STARTD) = 1998

Produces this report:

PROJNO  STARTD      ENDD        TIMESTAMP
------  ----------  ----------  --------------------------
1409    1998-06-15  1999-12-31  1996-03-13-09.12.57.149572
1410    1998-09-29  2000-03-31  1996-03-13-12.18.23.402917

Date/time functions (see Table 1, following) can be used wherever an expression can be used. The first or only argument of each of these functions is an expression giving the value to be manipulated.