Excerpt from John O. Honnold, Uniform Law for International Sales under the 1980 United Nations Convention, 3rd ed. (1999), pages 193-194. Reproduced with permission of the publisher, Kluwer Law International, The Hague.
§171 Article 18(2) (supra at §161) provides that an acceptance is not effective "if the indication of assent does not reach the offeror within the tine he had fixed...." The offeror’s statement fixing the time for acceptance may be ambiguous if it states a period of time (e.g., 15 days) for acceptance and does not specify when the period starts to run or does not deal with the effect of holidays.
"(1) A period of time for acceptance fixed by the offeror in a telegram or a letter begins to run from the moment the telegram is handed in for dispatch or from the date shown on the letter or, if no such date is shown, from the date shown on the envelope. A period of time for acceptance fixed by the offeror by telephone, telex or other means of instantaneous communication, begins to run from the moment that the offer reaches the offeree.
"(2) Official holidays or non-business days occurring during the period for acceptance are included in calculating the period. However, if a notice of acceptance cannot be delivered at the address of the offeror on the last day of the period because that day falls on an official holiday or a non-business day at the place of business of the offeror, the period is extended until the first business day which follows."
Article 20 is merely a guide to interpreting the offeror’s statements. Under Article 18(2) the offeror may "fix" the time for acceptance: A statement such as "You may accept this offer within ten days after this offer reaches you" would override the interpretive rule of Article 20(1). The offeror’s intention could be shown by less explicit language. Suppose that on June 1 Seller mails an offer to Buyer and states, "You will have five days to consider this offer." The mails between Seller and [page 193] Buyer normally take four or five days for delivery. It would be inconsistent with the expressed intention of the offer to start the five-day period on June 1. Article 20 thus plays the modest role of answering questions concerning the meaning of the offer when no answer is provided by the usual rules for interpreting the statements of a party. See Art. 8, supra at §§106–111. [page 194]
FOOTNOTES: Chapter on Article 20
1. Art. 20 is based on Art. 18 of the 1978 Draft Convention, subject to drafting changes in paragraph (2). Paragraph (1) is similar to ULF 8(2). Paragraph (2) (the effect of holidays) was based on UNCITRAL Arbitration Rules (1976) Art. 2(2), VII yearbook 22–27; Cf. Convention on the Limitation Period in the International Sale of Goods (1974) Art. 29 (A/CONF. 63/15), V Yearbook 213, 23 Am. J. Comp. L. 356 (1976).