VBA- How to search date in array of dates coming from excel

I am trying to write a simple function in VBA which takes as input a date and an array of dates both coming from Excel. It then returns true if the given date is part of the array or false otherwise.

My problem is that arrays coming from excel are 2 dimensional but I always pass in a 1 dimensional array. In other words, a column and a row value so I can check values in my array but I pass in a 1 dimensional array.

Here is my code:

Function IsInArray(ByVal MyDate As Date, ByRef Holiday_Calendar As Range) As Boolean
Dim length As Integer
length = WorksheetFunction.Count(Holiday_Calendar)
Dim counter As Integer
'counter = 0

For counter = 0 To length
If Holiday_Calendar(counter) = MyDate Then
IsInArray = True
End If
Next counter

IsInArray = False
End Function

via Chebli Mohamed