SAP Sybase IQ 16: Missing DATEROUND() I'm just wondering what might can be wrong

I was trying to round a date by its quarter. Beside some hacks I found the function DATEROUND, which I was thinking of based of documentation is able to do so. So I've build up a little test: 

SELECT DATEROUND(qq, now());


which failed with 


  Feature 'dateround' not implemented. 


Is this a bug inside documentation or did I just miss to enable something? Or is there maybe another easy solution without a case construct for getting this function?
Use the T-SQL compatible DATEPART construct to obtain the quarter, and construct the date from that.

For instance using T-SQL on SQL Server:

SELECT CONVERT(DATETIME, CONVERT(VARCHAR(4), DATEPART(YEAR, GETDATE())) + 
    STUFF(
        '00'
        , 3 - (LEN(1+(DATEPART(QUARTER, GETDATE()) * 3) - 3))
        , LEN(1+(DATEPART(QUARTER, GETDATE()) * 3) - 3)
        , 1+(DATEPART(QUARTER, GETDATE()) * 3) - 3
        ) +
    '01');


Returns 2015-01-01 00:00:00.000, the start of the current quarter of 2015.

According to the documentation for Sybase IQ 15; you'd need to modify the above to something like (I can't check the syntax since I don't have Sybase IQ on this machine):

SELECT CONVERT(DATETIME, CONVERT(VARCHAR(4), DATEPART(YEAR, GETDATE())) + 
    STUFF(
        '00'
        , 3 - (LENGTH(1+(DATEPART(QUARTER, GETDATE()) * 3) - 3))
        , LENGTH(1+(DATEPART(QUARTER, GETDATE()) * 3) - 3)
        , 1+(DATEPART(QUARTER, GETDATE()) * 3) - 3
        ) +
    '01');


See http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc38151.1510/html/iqrefbb/X315942.htm for details.