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1. This Convention shall enter into force on the earliest first of January which falls at least three months after a minimum of seventeen States or Customs or Economic Unions referred to in Article 11 above have signed it without reservation of ratification or have deposited their instruments of ratification or accession, but not before 1 January 1988.
2. For any State or Customs or Economic Union signing without reservation of ratification, ratifying or acceding to this Convention after the minimum number specified in paragraph 1 of this Article is reached, this Convention shall enter into force on the first of January which falls at least twelve months but not more than twenty-four months after it has signed the Convention without reservation of ratification or has deposited its instrument of ratification or accession, unless it specifies an earlier date. However, the date of entry into force under the provisions of this paragraph shall not be earlier than the date of entry into force provided for in paragraph 1 of this Article.