The date for the referendum is not specified in the question, so it is unclear which referendum is being referred to. However, based on the search results, there are several referendums happening in different countries on different dates. Here is a summary of the information found:

• In California, referenda can qualify for the statewide ballot up to 31 days before an election, and the next election day is November 5, 2024.
• In Australia, the Voice to Parliament referendum will be held on Saturday, October 14, 2023, and early voting will begin about two weeks beforehand.
• There is no information found on the date of any referendums in the United States in 2023.

Therefore, the specific date for the referendum cannot be determined without additional information.