Duration Time Tracker

[whatisbam]

I'm working on my first Power Bi dashboard.

I have very limited knowledge on PB & DAX.

Need some help pulling duration in hh:mm:ss from a table to display in a tile. 
I've been able to successfully pull the Current Time and Start Time from the linked spreadsheet.

Duration will display as 1/1/1900 12:48:04 instead of hh:mm:ss.

The Current Time refresh issue was solved by generating a new measure and using that instead of pulling the =NOW() from the table.

I've found links explaining that I may have to convert all dates and times into second and back to dates and hh:mm:ss inside PB.

Any help, advice and links are much appreciated.

Below is an outline of what I'm trying to do.

[lbendlin · Accepted solution]

Duration = 
 var d = [Current Time]-[Start Time]
 return INT(d*24) & FORMAT(d,":nn:ss")