count files extensions files for each month based on modified date

[abdelfattah]

Hi,
I need fixing code to count how many files extensions for each month based on modified date in folders and subfolders and sub-subfolders
I put expected result should be in sheet1

Sub FindCountU()

Dim acs As Worksheet
Dim n As Workbook
Dim FolderName As String, Filename As String, ext$
Dim i As Integer, a$(), cnt&, j&, t&, ct&, f, fs
Dim dict As Object, ltst As Date, fin As Date
Set fs = CreateObject("Scripting.FileSystemObject")
Set dict = CreateObject("scripting.dictionary")
    FolderName = "C:\Users\ABB\Desktop\data" & "\"
    Filename = Dir(FolderName & "*.*")
    Do While Filename <> ""
        cnt = cnt + 1
        Filename = Dir()
    Loop


    ReDim a(1 To cnt, 1 To 2)
    Filename = Dir(FolderName & "*.*")
    Do While Filename <> ""
        i = i + 1
        Set f = fs.GetFile(FolderName & Filename)
        ext = Mid(Filename, InStr(1, Filename, ".") + 1)
        a(i, 1) = ext
        a(i, 2) = f.datelastmodified
        If Not dict.exists(ext) Then
            dict.Add ext, i
        End If
    Filename = Dir()
    Loop
    ct = 0
    ltst = #1/1/2001#
    fin = #1/1/2001#
    For j = 0 To dict.Count - 1
        For t = LBound(a) To UBound(a)
            If dict.keys()(j) = a(t, 1) Then
                ct = ct + 1
                If Format(a(t, 2), "mm/dd/yyyy") > Format(ltst, "mm/dd/yyyy") Then
                    ltst = Format(a(t, 2), "mm/dd/yyyy")
                    fin = Format(a(t, 2), "mm/dd/yyyy")
                End If
            End If
        Next t
        Sheets("SHEET1").Cells(j + 2, 1).Value = j + 1
        Sheets("SHEET1").Cells(j + 2, 2).Value = dict.keys()(j)
        Sheets("SHEET1").Cells(j + 2, 3).Value = ct
        Sheets("SHEET1").Cells(j + 2, 4).Value = UCase(Format(fin, "mmm"))
        ct = 0
        ltst = #1/1/2001#
        fin = #1/1/2001#
    Next j
End Sub

thanks