Excel, VB - Serialize an 8 digit date to mm/dd/yy - date

Question

ISSUE
I am trying to convert a 8 digit number into a date while in an array. Examples of the entries are 12282009 or 12202007. There are other malformed entries in the field including dates entered as strings. I want the 8 digit number to be formatted as 12/28/09 or 12/20/07 respectively. I keep getting a type mismatch error on the third to last line below. How do I do this??
CODE
Dim del()
ReDim del(1 To importwsRowCount, 1 To 1)
del = Range("AH1:AH" & importwsRowCount).Value
Dim delChars As Long
Dim delType As String
For i = LBound(del, 1) To UBound(del, 1)
delChars = Len(del(i, 1)) 'Determine length of entry
If IsNumeric(del(i, 1)) = True Then 'Determine datatype of entry
delType = "Numeric"
del(i, 1) = Abs(del(i, 1))
Else
delType = "String"
del(i, 1) = UCase(del(i, 1))
End If
If delType = "Numeric" Then
If delChars = 8 Then
del(i, 1) = DateSerial((Right(del(i, 1), 4)), (Left(del(i, 1), 2)), (Mid(del(i, 1), 3, 2))) '<-- TYPE MISMATCH ERROR
End If
End If
ENTRY TEMPLATES
SEPT. 25, 20 (No year, no year! Delete.)
SEPT (No year, useless, delete.)
N/A (Rubbish! Deleted.)
LONG TIME AG (What moron thought this was a good idea, delete.)
JUNE 30, 200 (Apparently the field will only hold 12 characters, delete.)
CHARGED OFF (Useless, delete.)
94 DAYS (Take all characters preceding space and subtract from other field containing order date to obtain delinquent date.)
94 DPD (DPD in someones bright mind stands for Days Past Due I believe. Same as above.)
2008-7-15 12 (Not sure what additional number is, take all characters before space and transform.)
INVALID (Delete.)
BLANK (Do nothing.)
4/2/4/09 (Malformed date, delete.)
1/1/009 (Same as above.)
12282009 (Use nested LEFT and RIGHT and CONCATENATE with / in between.)
9202011 (Add leading zero, then same as above.)
92410 (Add leading zero, this will transform to 09/24/10)
41261 (Days since 31/12/1899, this will transform to 12/08/12)
1023 (Days since delinquent, subtract from ORDER DATE to get delinquent date.)
452 (Same as above.)
12 (Same as above.)
1432.84 (Monetary value, mistakenly entered by low IQ lackey. Delete.)

Answer 1

Right(Left(del(i, 1), 2), 6) is nonsensical.
The Left(del(i, 1), 2) part happens first and returns a 2-character string. If you then apply Right(..., 6) to that 2-character string you get an error.
The Mid function is needed here: Mid(del(i, 1), 3, 2)
Running the Abs function earlier changed the array entry from being a Variant with subtype String to being a Variant with subtype Double. This shouldn't necessarily affect the Left/Mid/Right functions but try:
del(i, 1) = CStr(del(i, 1))
del(i, 1) = DateSerial((Right(del(i, 1), 4)), (Left(del(i, 1), 2)), (Mid(del(i, 1), 3, 2)))
We need to identify what the actual value causing the error is so:
If delType = "Numeric" Then
If delChars = 8 Then
On Error Goto DateMismatchError
del(i, 1) = DateSerial((Right(del(i, 1), 4)), (Left(del(i, 1), 2)), (Mid(del(i, 1), 3, 2))) '<-- TYPE MISMATCH ERROR
On Error Goto 0
End If
End If
' at the end of your Sub or Function - I'm assuming Sub here
Exit Sub
DateMismatchError:
MsgBox "Date mismatch: error number " & Err.Number & ", " & Err.Description & _
" caused by data value: |" & del(i, 1) & "| at row " & i & ". Original data " & _
"value is |" & Range("AH" & i).Value2 & "|, displayed value is |" & _
Range("AH" & i).Text & "|, number format is |" & Range("AH" & i).NumberFormat & "|"
End Sub

Answer 2

You can use this shorter code to replace your array elements with formatted dates
It cuts down the amount of testing inside the loop to two IFs. If numeric test is run first - there is no point running a longer lenint test for strings that are not 8 characters
The string functions Left$, Mid$ etc are much quicker than their variant cousins Left, Mid etc
I have made a substituion for your importwsRowCount variable in the code below
Updated code to handle and dump results, now handles string tests and non-compliantnumbers as per barrowc comments
The code below puts the new dates into a second array, skipping the invalid dates
The second array is then dumped at `AI``
Sub ReCut2()
Dim del()
Dim X()
Dim lngCnt As Long
del = Range("AH1:Ah10").Value2
ReDim X(1 To UBound(del, 1), 1 To UBound(del, 2))
Dim delChars As Long
Dim delType As String
For lngCnt = LBound(del, 1) To UBound(del, 1)
If IsNumeric(del(lngCnt, 1)) Then
If Len(Int((del(lngCnt, 1)))) = 8 Then X(lngCnt, 1) = DateSerial(Right$(del(lngCnt, 1), 4), Left$(del(lngCnt, 1), 2), Mid$(del(lngCnt, 1), 3, 2))
End If
Next
[ai1].Resize(UBound(X, 1), UBound(X, 2)).Value2 = X
End Sub