Notes: All timings are represented in 24+ hour notation in local time of Ashburn, United States with DST adjustment (if applicable).
Hours past midnight are higher than 24:00 and fall on next day. In Panchang day starts and ends with sunrise.
A day before Diwali Puja, Hanuman Puja is performed in some parts of India especially in Gujarat. The day of Hanuman Puja coincides with the day of Kali Chaudas. It is believed that the bad spirits are most powerful during the night of Kali Chaudas. Lord Hanuman, who gives strength to fight evil spirits, is worshipped to seek strength, power and the protection from all sorts of bad spirits.
According to another legend, Diwali is celebrated to mark the return of Lord Rama to Ayodhya after defeating demon Ravana and completing His fourteen years of exile. The devotion and dedication of Hanuman pleased Shri Rama so much that He blessed Hanuman for getting worshipped before Him. Hence people worship God Hanuman a day before Diwali celebrations.
The very same day is observed as Shri Hanuman Jayanti at Hanumangarhi (हनुमानगढ़ी) temple in Ayodhya. However most of the people in North India celebrate Hanuman Jayanti on Chaitra Purnima.