Special Ozone Day 2005 issue: - Message by UN Secretary-General Kofi Annan on International Day for the Preservation of the Ozone Layer, 16 September 2005. - International Ozone Day to mark the signing of Montreal Protocol on 16 September; Vienna Convention to celebrate two decades of protecting the ozone layer on 21 September; "An extraordinary success story - but saving ozone layer an unfinished business," says UNEP