Make duration a number field. I gather 60 represents 60 minutes.
Time fields record time in seconds so your time out field can be a calculation field set to return time as:
Time In field + Duration * 60
This will also work if both Time In and Time Out are TimeStamp fields--which is often a better approach if your time intervals may cross the midnight hour.
That works great, Thanks for all your help i appriciate it.