Help with an expression for a gauge chart

[#1]

Hi,

I am trying to create a gauge to display how long jobs take to run.  There would be one gauge per job.  It should look similar to the attached image.

I have a Start_Date field that stores the start date and time of jobs and an End_Time field that stores the end date and time of jobs. 

The range for the gauge should start at 5 p.m. on the prior day (7/29) and finish at 5 a.m. the current day (7/30).

I’m unclear on what my expression should be.  I need to identify what the job should be but this expression does not return any data:

$({<collct_id={'1'}>}End_Time)

An example would be if a job started at 7/29/2013 at 6:12:12 PM and finished at 7/30/2013 1:20:00 AM I would need the duration to be 7 hours, 7 minutes and 58 seconds and the needle to show this.

Any help would be greatly appreciated.

[#2]

Please disregard.  I've asked around and it doesn't sound like this is possible using a gauge chart.  I'm going to go with a Gantt chart instead.  I found a great article on this in the QV Development Blog:

http://community.qlik.com/blogs/qlikviewdesignblog/2012/06/01/recipe-for-gantt-chart