Calculating time of incident resolution after escalation?

Content

Hello,

I want to add column in report to calculate time taken to resolve incident after that incident is escalated. It should display time in hours and minutes format.
I can get time difference by date_diff( incidents.closed, incidents.escldate ) but can't get the desired output in columns. I have gone through incident performance table documentation but couldn't find anything for this. Can someone please suggest a way or solution?

Version

Oracle Service Cloud 18A