Cannot convert value #datetime to Date

I'm attempting to calculate the number of working days for each Employee, however I'm running into an issue when attempting to calculate it. 

Using the supplied function below, I use this to calculate the number of 

(StartDate as date, EndDate as date) as number =>

let

    DateList = List.Dates(StartDate, Number.From(EndDate - StartDate), #duration(1, 0, 0, 0)),
    RemoveWeekends = List.Select(DateList, each Date.DayOfWeek(_, Day.Monday) < 5),
    RemoveHolidays = List.RemoveItems(RemoveWeekends),
    CountDays = List.Count(RemoveHolidays)
in
    CountDays

I then invoke a Custom Function selecting my BeginDate column and EndDate column

 However it's giving me all Errors in the NWD column and saying this error message below. What am I doing wrong here, there's something I'm missing that's causing this.

Expression.Error: We cannot convert the value #datetime(2013, 5, 7, 22, 0, 0) to type Date.
Details:
Value=5/7/2013 10:00:00 PM
Type=[Type]