Guide to the use of this commentary
The Secretariat Commentary is on the 1978 Draft of the CISG, not the Official Text, which re-numbered most of the articles of the 1978 Draft. The Secretariat Commentary on article 18 of the 1978 Draft is quoted below with the article references contained in this commentary conformed to the numerical sequence of the Official Text, e.g., article 18 [draft counterpart of CISG article 20].
To the extent it is relevant to the Official Text, the
Secretariat Commentary on the 1978 Draft is perhaps the
most authoritative source one can cite. It is the
closest counterpart to an Official Commentary on the
CISG. A match-up of this article of the 1978 Draft
with the version adopted for the Official Text is
necessary to document the relevancy of the Secretariat
Commentary on this article. See the match-up for this article
for a validation of citations to this
Secretariat Commentary. This match-up indicates that article 18 of the 1978 Draft
and CISG article 20 are substantively identical.
Text of Secretariat Commentary on article 18 of the 1978 Draft
[draft counterpart of CISG article 20] [Time fixed for acceptance]
PRIOR UNIFORM LAW
ULF, article 8(2). UNCITRAL Arbitration Rules, article 2(2).
1. Article 18(1) [draft counterpart of CISG article 20(1)] provides a mechanism for the calculation of the commencement of the period of time during which an offer can be accepted.
2. If a period of time for acceptance is of a fixed length, such as 10 days, it is important that the point of time at which the 10-day period commences be clear. Therefore, article 18(1) [draft counterpart of CISG article 20(1)] provides that a period of time for acceptance fixed by an offeror in a telegram "begins to run from the moment the telegram is handed in for dispatch."
3. In the case of a letter the time runs "from the date shown on the letter" unless no such date is shown, in which case it runs "from the date shown on the envelope." This order of preference was chosen for two reasons: first, the offeree may discard the envelope but he will have the letter available as the basis for calculating the end of the period during which the offer can be accepted and second, the offeror will have a copy of the letter with its date but will generally have no record of the date on the envelope. Therefore, if the date on the envelope had not been checked, the offeror could not know the termination date of the period during which the offer could be accepted (OFFICIAL RECORDS, p. 25).