September 23 holds significance in Indian history for several political, military, cultural and social developments. The day marks the birth anniversaries of prominent Indians including freedom fighter Yusuf Meherali, poet Ramdhari Singh 'Dinkar', actress Tanuja, actor Prem Chopra and scientist Asima Chatterjee.

It is also associated with important events such as the Battle of Haifa during World War I and the 1965 India-Pakistan ceasefire. September 23 is observed globally as the International Day of Sign Languages.
One of the important military events associated with September 23 is the Battle of Haifa in 1918. Indian cavalry units, including troops from Mysore, Jodhpur and Hyderabad, played a significant role in the Allied victory at Haifa during the First World War.
September 23 also marks the 1965 India-Pakistan ceasefire, which brought the Indo-Pak war of 1965 to an end following United Nations intervention.
Another significant event took place on September 23, 2018, when the Government of India launched Ayushman Bharat, a major healthcare initiative aimed at expanding health coverage for eligible families.
Several notable Indians were born on this date:
Notable public figures associated with September 23 include V. S. Srinivasa Sastri (1862), an Indian politician, educationist and diplomat; Yusuf Meherali (1903), who was active in the freedom movement; and Mahendra Singh Tikait (1935), a prominent farmers' leader associated with the Bharatiya Kisan Union.
September 23 is also the birth anniversary of several Indian cricketers. Anshuman Gaekwad (1952) represented India in Test and ODI cricket and later served as a coach. Ambati Rayudu (1985) played international cricket for India and was also a prominent Indian Premier League player. Other domestic cricketers have also been born on this date.
The International Day of Sign Languages is observed every year on September 23. The United Nations proclaimed the day through Resolution A/RES/72/161 in December 2017, with the first observance held in 2018. The date commemorates the establishment of the World Federation of the Deaf in 1951. The observance highlights the importance of sign languages in ensuring the rights, inclusion and participation of deaf people.
September 23 is also observed internationally as International Celebrate Bisexuality Day, also known as Bi Visibility Day, which has been observed since 1999.
September 23 brings together important milestones from India's freedom struggle, military history, healthcare initiatives, literature, science, cinema and cricket. The day also highlights global efforts toward linguistic accessibility and inclusion through the International Day of Sign Languages.