Using Microsoft’s PowerShell cmdlet: New-TimeSpan you can see how long an application has been running
New-TimeSpan -Start (get-process calc).StartTime
You will want to sub the word “calc” out for whatever application you are using. You can type “get-process” to see a list of all the ProcessNames running on the system.
For more examples, check out: https://technet.microsoft.com/en-us/library/Ee176916.aspx