Her er løsningen, til dem der skulle være interesseret
SELECT modulusTime, modulusMinut, count(Modulus)
FROM [SELECT
int( ((hour(opkaldstidspunkt) * 60 + minute(opkaldstidspunkt)) * 60 + second(opkaldstidspunkt)) / (5 * 60)) * (5 * 60) AS Modulus,
int(Modulus / 3600) AS modulusTime,
int((Modulus - modulusTime * 3600) / 60) AS modulusMinut
FROM statistik_hvd
]. AS [%$##@_Alias]
GROUP BY modulusTime, modulusMinut, Modulus
ORDER BY Modulus;