I'm trying to learn VBA, but I'm really stuck.

Each month new data (from the previous month) is pasted over the old data. The number of days each month changes due to nonwork days. I've tried clearing the cells and pasting data in blank cells, but this messes up the associated charts and graphs. Eventually I will learn how to have VBA create new charts, but I'm not there yet. I want to delete entire rows with data before the last month, day 1.

I've read so many posts and I've tried so many ways. I'm just not getting it and I'm losing my mind!

Sub ltest()

Dim d As Date
d = DateAdd("y", -1, Date)
LastMonth = Month(DateAdd("m", -1, Date))

Dim w As Long
For w = Sheet1.[a4].SpecialCells(xlCellTypeLastCell).Row To 1 Step -1
    Debug.Print Cells(w, "A").Value
    If CDate(Cells(w, "A")) < CDate(LastMonth) Then
        Cells(w, "A").EntireRow.Delete
    End If
Next w

End Sub

I hope that I have posted this correctly and I really appreciate any help.