13 September 2023

• 256th day of the year. There were then 109 days left in 2023.
• 37th Wednesday of 2023.
• on the 37th 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.

• Day of the Children Heroes (Día de los Niños Héroes) - Mexico
• International Chocolate Day (Día Intl. Del Chocolate) - Popular in: Spain
• Día del Bibliotecario - Argentina
• Dia do Programador - Brazil
• National Quiet Day - United Kingdom
• Roald Dahl Day - United Kingdom