18 September 2023

• 261st day of the year. There were then 104 days left in 2023.
• 38th Monday of 2023.
• on the 38th week of 2023 (using ISO standard week number calculation).
• Birthstone for this day: Sapphire

There are no major holidays or observances in Australia for this date.

• National Cheeseburger Day - Popular in: United States, Canada
• Federal Fast (Eidgenössische Danktag, Busstag und Bettag - Beobachten) - Switzerland
• Chile Independence Day - Popular in: United States
• Fiestas Patrias - Chile
• Dia da Independência do Chile - United States
• AIDS and Aging Awareness Day - United States
• Día de la Constitución - United States
• European Heritage Days Starts - European Union