Returns an integer between 1 and 4 which represents the quarter of the year in which the date resides. For example, any dates in January, February, or March will return the integer 1.
The argument must be a date or a timestamp.
Example:
Using the PROJECT table, return the quarter in which project 'PL2100' ended (PRENDATE).
SELECT QUARTER(PRENDATE) FROM PROJECT WHERE PROJNO = 'PL2100'
Returns 3 when using the sample table.