Date Time Conversion/ Filter Issue - AM/PM - format problem.

I have some date time stamp records from our LMS system (field is called Complete By).

Orginal string examples

11/13/2015 11:59:59 PM UTC-05:00

9/8/2016 11:59:59 PM UTC-04:00

I am trying to have the tool convert these to actual date strings (so I can use the calendar filter). I was able to use a formula to strip out the UTC-5:00 text.  

LEFT([Complete By],Length([Complete By])-10)

I then tried to use the Date Time Parse tool to convert what was left to a Date time field. However, I kept getting an error that it wasn't valid. I then broke the string into 3 segments by Date time and AM/PM.  Even when I try to covert the date field only now I get an error. See below

ConvError: Select (11): Date: "11/13/2015" is not a valid Date

ConvError: Select (11): Date: "9/8/2016" is not a valid Date

Is there some step I am missing to allow Alteryx to interpret the string that includes the Date time and the AM/PM as a valid date field? 

Thanks,

Adam