Hi DB, If you don't need column B and just want to colour the dates, this should do it. 

Option Compare Text
Option Explicit
 
Private Sub Worksheet_Change(ByVal target As Range)
    Dim Rng1 As Range
    Set Rng1 = Range("A2:A65536")
    If Intersect(target, Rng1) Is Nothing Then Exit Sub
Application.EnableEvents = False
    DoFormat2
    Application.EnableEvents = True
End Sub
 
Sub DoFormat2()
Dim Cell As Range
    Dim Rng1 As Range
Set Rng1 = Range("a2:a65536").SpecialCells(xlCellTypeConstants, 1)
For Each Cell In Rng1
    Debug.Print Cell.Address
        Select Case Int(Now()) - Cell.Value
        Case vbNullString
            Cell.Interior.ColorIndex = xlNone
            Cell.Font.Bold = False
        Case Is > 120
            Cell.Interior.ColorIndex = 3
            Cell.Font.Bold = True
        Case Is > 90
            Cell.Interior.ColorIndex = 36
            Cell.Font.Bold = True
        Case Is > 60
            Cell.Interior.ColorIndex = 35
            Cell.Font.Bold = True
        Case Is > 30
            Cell.Interior.ColorIndex = 6
            Cell.Font.Bold = True
        Case Else
            Cell.Interior.ColorIndex = xlNone
            Cell.Font.Bold = False
        End Select
    Next
End Sub

A slight mod. to your formatting will give your numbers column

For Each Cell In Rng2
        Select Case Cell.Value
        Case vbNullString
            Cell.Interior.ColorIndex = xlNone
            Cell.Font.Bold = False
        Case Is > 120
            Cell.Interior.ColorIndex = 3
            Cell.Font.Bold = True
            Cell.Offset(0, 5).Value = 120
        Case Is > 90
            Cell.Interior.ColorIndex = 36
            Cell.Font.Bold = True
            Cell.Offset(0, 5).Value = 90
      Case Is > 60
            Cell.Interior.ColorIndex = 35
            Cell.Font.Bold = True
            Cell.Offset(0, 5).Value = 60
        Case Is > 30
            Cell.Interior.ColorIndex = 6
            Cell.Font.Bold = True
            Cell.Offset(0, 5).Value = 30
        Case Else
            Cell.Interior.ColorIndex = xlNone
            Cell.Font.Bold = False
            Cell.Offset(0, 5).Value = "-"
        End Select
    Next