how to select OThours from intime and outtime

Apr 3 2017 11:39 AM

I have a table in that table I have a column name like attdate,in time ,out time like below format attdate in time out time 12-03-17. 08:45. 20.37 13-03-17. 08:35. 20:45 if out time greater than 18:00 calculate OThrs.which datatype I have to store OThrs.if OThrs >than 2.30 means round off to 3