Krishna Janmashtami in 2023 was celebrated primarily on Wednesday, September 6, but the festival events extended into September 7 as well. This is because the auspicious Ashtami Tithi (the lunar day associated with Krishna's birth) began in the afternoon of September 6 and ended late afternoon on September 7, 2023. The Rohini Nakshatra, significant for Lord Krishna's birth, also spanned from the morning of September 6 to mid-morning of September 7. Due to this timing, the main celebrations took place on September 6, with some rituals and events continuing into September 7, including the popular Dahi Handi event on the 7th.
Thus, Krishna Janmashtami 2023 was observed over two days: September 6 and 7.