Effective date versus commencement date

The dates a law can carry

A single law can have a date of adoption, a date of assent or signature, a date of publication, a date of commencement or entry into force, a date of application and a compliance date. Different systems use different words for these. The key point for a dated record is that the date a law was passed is often not the date it began to bind anyone.

EUR-Lex shows this for Regulation (EU) 2024/2809, the EU Listing Act. Its date of document is 23 October 2024 and its first date of entry into force is 4 December 2024 ⁵. Some of its changes to the Market Abuse Regulation apply only from 5 June 2026, according to the Finnish Financial Supervisory Authority ⁶.

Default rules when a law is silent

Many countries have an interpretation law that fills the gap when an Act sets no start date.

Beginning of the day

Commencement rules often fix the exact moment as well as the day. The UK Interpretation Act 1978 says an Act with a named start day comes into force at the beginning of that day ¹. The Canadian Interpretation Act says an enactment expressed to take effect on a particular day takes effect on the expiration of the previous day ². Both mean that the law applies to the whole of the named day.

Canada fixes how the assent date is recorded. The Clerk of the Parliaments endorses on every Act, immediately after its title, the day, month and year of assent, and the endorsement forms part of the Act ².

Effective date and compliance date

US agencies often give two dates for a new rule. The SEC said its 2023 cybersecurity disclosure rules would become effective 30 days after publication of the adopting release in the Federal Register ⁴. It set the start of Form 8-K incident disclosure at the later of 90 days after Federal Register publication or 18 December 2023, and gave smaller reporting companies an extra 180 days ⁴.

So one rule produced an adoption date of 26 July 2023, a publication date, an effective date and more than one compliance date ⁴. A timeline that lists only the adoption date would suggest the duty began months earlier than it did.

Passed but not yet in force

A law can be on the statute book without being in force. legislation.gov.uk lists an outstanding change for the UK version of the Market Abuse Regulation: its revocation by the Financial Services and Markets Act 2023 ⁷. The site says this change has not yet been applied to the text, which it describes as up to date for changes in force on or before 6 November 2026 ⁷.

A law can start on a fixed date set in advance. In Hong Kong, the statutory duty to disclose inside information in Part XIVA of the Securities and Futures Ordinance took effect on 1 January 2013, according to the SFC's guidelines published in June 2012 ⁸.