CREATE FUNCTION [dbo].[func_OrpheusToDate]
(
    @stDate as integer
)
RETURNS date
AS
BEGIN
DECLARE @sql_date_tmp DATE = NULL;
DECLARE @lyear   INTEGER;
DECLARE @lmonth  INTEGER;
DECLARE @lday    INTEGER;
DECLARE @sdatstr VARCHAR(10);
DECLARE @i       INTEGER;
DECLARE @j       INTEGER;

IF (@stDate IS NULL) OR (@stDate <= 0) OR (@stDate >= 999999)
    SET @sql_date_tmp = NULL
ELSE IF (@stDate <= 59)
BEGIN
    SET @sql_date_tmp = GETDATE();
    SET @lyear = 1600;

    IF (@stDate <= 30)
    BEGIN
        SET @lmonth = 1;
        SET @lday   = @stDate +1;
    END
    ELSE
    BEGIN
        SET @lmonth = 2;
        SET @lday   = @stDate -30;
    END;

    SET @sdatstr = CONVERT(VARCHAR, @lday) + '/' + CONVERT(VARCHAR, @lmonth) + '/' + CONVERT(VARCHAR, @lyear);
    SET @sql_date_tmp = CONVERT(DATE, @sdatstr);
END
ELSE
BEGIN
    SET @sql_date_tmp = GETDATE();

    SET @i = (4*(@stDate -59))-1;

    SET @j = (4*ROUND((@i % 146097)/4, 0,1))+3
    SET @lyear = (100*ROUND(@i/146097, 0, 1))+ROUND(@j/1461, 0, 1)

    SET @i = (5*ROUND(((@j % 1461)+4)/4, 0, 1))-3;
    SET @lday = ROUND(((@i % 153)+5)/5, 0, 1);

    SET @lmonth = ROUND(@i/153, 0, 1);

    IF (@lmonth < 10)
        SET @lmonth = @lmonth +3
    ELSE
    BEGIN
        SET @lmonth = @lmonth -9;
        SET @lyear = @lyear +1;
    END;

    SET @lyear = @lyear + 1600;

    SET @sdatstr = CONVERT(VARCHAR, @lyear) + '/' + CONVERT(VARCHAR, @lmonth) + '/' + CONVERT(VARCHAR, @lday);

    SET @sql_date_tmp = CONVERT(DATE, @sdatstr);
END

RETURN @sql_date_tmp
END