CREATE FUNCTION "IsCurMonth" (
IN "ADate" DATE)
RETURNS BOOLEAN
BEGIN
 DECLARE Result BOOLEAN DEFAULT False;
 DECLARE EndDate, StartDate DATE;
 DECLARE iYear, iMonth INTEGER;

 SET EndDate = CURRENT_DATE;
 SET iYear = EXTRACT(YEAR, EndDate);
 SET iMonth = EXTRACT(MONTH, EndDate);
 SET StartDate = CAST(CAST(iYear AS VARCHAR) + '-' + CAST(iMonth AS VARCHAR) + '-01' AS DATE);

 IF ADate BETWEEN StartDate AND EndDate THEN
   SET Result = True;
 ELSE
   SET Result = False;
 END IF;

 RETURN Result;
END

DESCRIPTION 'Boolean function to return TRUE if the given date belongs to current month.'