As a regulatory authority, it doesn't specify that the government is allowed to select a date but that the date would be “by December 31, 2029”. I should say also that the Governor in Council may not select a date. There's no prescribing of a date permitted by the regulatory authority. It specifically uses the language that the prohibition is “by December 31, 2029”.
On December 6th, 2023. See this statement in context.