How to Calculate “Within 21 Days of Shipment” under ISBP 821

Intro

 Time calculations under Letters of Credit often look simple, yet the word “within” continues to cause confusion — especially when readers focus on the example given in ISBP 821 paragraph A14(b)(i) and wonder whether the permitted period should extend both before and after the shipment date.

 The following Q&A addresses a very practical question:

When an LC requires documents to be sent “within 21 days of shipment”, what dates are actually allowed?

Question

Dear Sir,

Good day to you, and Happy New Year 2026.

I refer to ISBP 821 paragraph A14(b)(i), which states:

“For the purpose of calculation of a period of time, the term ‘within’ when used in connection with a date or event excludes that date or the event date in the calculation of the period. For example, ‘within 2 days of (date or event)’ means a period of 5 days commencing 2 days prior to that date or event until 2 days after that date or event.”

In this example, the clause results in a five-day period.

I now have a letter of credit containing the following condition:

“A certificate is required from the beneficiary evidencing that the following documents have been sent directly by courier within 21 days of shipment to: XXYYXX.”

Assuming the shipment date is 21 January 2026, I would appreciate your guidance on the permissible dates for sending the documents.

Kind regards,

C.R. Nishanth

_______

Answer

Dear Nishanth,

Thank you for your question.

In practice, the expressions “within 21 days of shipment”, “within 21 days from shipment” and “within 21 days after shipment” are interpreted in the same way, then UCP 600 article 3 which says: “The word “before” or “after” when used to determine a period of shipment exclude the date mentioned” is clearer and more appropriate than ISBP 821 paragraph A14(b)(i).

The shipment date serves as the starting reference point, not the midpoint of the calculation.

Conclusion:

Where the shipment date is 21 January 2026, this day is excluded and the courier dispatch date shown in the beneficiary’s certificate must fall between 22 January and 11 February 2026 (inclusive).

I hope this clarifies the matter.

Best regards,

Mr. Old Man