> select firstname, lastname, > SEC_TO_TIME( sum(TIME_TO_SEC(endtime)-TIME_TO_SEC(starttime)) ) > from presence > where starttime between '2006-05-31 0:00:00' and '2006-05-31 > 23:59:59'; bingo SEC_TO_TIME and TIME_TO_SEC were lurking in the back of my mind and just hadn't surfaced vielen dank