VBA - Parsing Date from Free Form Text String - excel

Question

I am attempting to parse out clean target DATES from cells populated with free form TEXT STRINGS.
ie: TEXT STRING: "ETA: 11/22 (Spring 4.5)" or "ETA 10/30/2019 EOD"
As you can see, there is no clear standard for the position of the date in the string, rendering LEFT or RIGHT formulas futile.
I tried leveraging a VBA function that I found which essentially breaks up the string into parts based on spaces in the string; however it has not been working.
Public Function GetDate(ResNotes As String) As Date
Dim TarDate As Variant
Dim part As Variant
TarDate = Split(ResNotes, " ")
For Each part In ResNotes
If IsDate(part) = True Then
GetDate = part
Exit Function
End If
Next
GetDate = "1/1/2001"
End Function
I'm referring to the cells with text strings as "ResNotes", short for "Resolution Notes" which is the title of the column
"TarDate" refers to the "Target Date" that I am trying to parse out
The result of the custom GETDATE function in Excel gives me a #NAME? error.
I expected the result to give me something along the lines of "10/30/2019"

Answer 1

Unless you need VBA for some other part of your project, this can also be done using worksheet formulas:
=AGGREGATE(15,6,DATEVALUE(MID(SUBSTITUTE(A1," ",REPT(" ",99)),seq_99,99)),1)
where seq_99 is a named formula and refers to:
=IF(ROW($A$1:INDEX($A:$A,255,1))=1,1,(ROW($A$1:INDEX($A:$A,255,1))-1)*99)
*seq_99 generates an array of numbers {1;99;198;297;396;495;...
Format the cell with the formula as a Date of some type.
If there are no dates, it will return an error which you can either leave, or wrap the function in an IFERROR(your_formula,your_error_message)
Algorithm
Split the cell on the spaces
Replace each space with 99 spaces
Using the MID function, return an array of substrings 99 characters long
Apply the DATEVALUE function which will return either an error (if the substring is not a date) or a date serial number.
Since dates in Excel are serial numbers since 1/1/1900, we can use the AGGREGATE function to pick out a value, and ignore errors.

Answer 2

If you are getting #NAME then the code is not stored in a general module. It should NOT be in a worksheet module or ThisWorkbook module.
Also there are few errors in the code. Split returns a String Array. And since IsDate returns TRUE/FALSE the = True is not needed.
As per #MathieuGuindon we can change the string to a date in the code if found and return an error if not. For that we need to allow the return to be a variant.
Public Function GetDate(ResNotes As String)
Dim TarDate() As String
Dim part As Variant
TarDate = Split(ResNotes, " ")
For Each part In TarDate
If IsDate(part) Then
GetDate = CDate(part)
Exit Function
End If
Next
GetDate = "1/1/2001"
'Instead of a hard coded date, one can return an error, just use the next line instead
'GetDate =CVErr(xlErrValue)
End Function

Answer 3

Approach isolating the date string via Filter function
Just for fun another approach demonstrating the use of the Filter function in combination with Split to isolate the date string and split it into date tokens in a second step; finally these tokens are transformed to date using DateSerial:
Function getDat(rng As Range, Optional ByVal tmp = " ") As Variant
If rng.Cells.count > 1 Then Set rng = rng.Cells(1, 1) ' allow only one cell ranges
If Len(rng.value) = 0 Then getDat = vbNullString: Exit Function ' escape empty cells
' [1] analyze cell value; omitted year tokens default to current year
' (valid date strings must include at least one slash, "11/" would be interpreted as Nov 1st)
tmp = Filter(Split(rng.Value2, " "), Match:="/", include:=True) ' isolate Date string
tmp = Split(Join(tmp, "") & "/" & Year(Now), "/") ' split Date tokens
' [2] return date
Const M% = 0, D% = 1, Y& = 2 ' order of date tokens
getDat = VBA.DateSerial(Val(tmp(Y)), Val(tmp(M)), _
IIf(tmp(D) = vbNullString, 1, Val(tmp(D))))
End Function