Sub NextYear()
With ActiveDocument.Range
  With .Find
    .ClearFormatting
    .Text = "[0-9]{1,2}/[0-9]{1,2}/[0-9]{2,4}"
    .Replacement.Text = ""
    .Forward = True
    .Wrap = wdFindStop
    .MatchCase = False
    .MatchWholeWord = False
    .MatchWildcards = True
    .MatchSoundsLike = False
    .MatchAllWordForms = False
    .Execute
  End With
  Do While .Find.Found
    If Split(.Text, "/")(2) = Format(.Text, "yyyy") Then
      .Text = DateAdd("yyyy", 1, .Text)
    Else
      .Text = Format(DateAdd("yyyy", 1, .Text), "mm/dd/yy")
    End If
    .Collapse wdCollapseEnd
    .Find.Execute
  Loop
End With
End Sub