SELECT IF( DATE_FORMAT( Datum,  '%w' ) 
BETWEEN 1 
AND 5 ,  'RadniDan', DATE_FORMAT( Datum,  '%a' ) ) AS Dan, COUNT( DATE_FORMAT( Datum,  '%a' ) ) AS Ukupno
FROM zaposlenik
GROUP BY IF( DATE_FORMAT( Datum,  '%w' ) 
BETWEEN 1 
AND 5 ,  'RadniDan', DATE_FORMAT( Datum,  '%a' ) )