Average duration of time fields

[Taylorcc]

Hello, 

I have created a duration field based off start time and end time fields: Interval(SCEndTime-SCStartTime,'h:mm') as SCDuration

I need to find the average of Duration for all of my data 

Avg(SCDuration) isnt working correctly 

What am I doing wrong?  

[lironbaram]

hi 

when you say average doesn't work well 

what do you mean 

the result aren't correct ?