Send email from Excel using Outlook

Can you explain what conditions exist on the filter for column A?

Sub HideRows()

    Dim lRow As Long
    Dim i As Long
    Dim iDate As Long
    
    
    Application.ScreenUpdating = True
    
    lRow = Range("A65536").End(xlUp).Row
    
    For i = 4 To lRow
        If IsDate(Range("A" & i).Value) = True Then
            iDate = DateDiff("d", Date, Range("A" & i).Value)
                If iDate < 0 Or iDate > 7 Then
                Cells(i, 1).EntireRow.Hidden = True
                End If
        End If
    Next i
    
    Call SendEmail
            
End Sub