DEEPAVALI Date : Deepavali is celebrated in South-India in the states Tamil Nadu, Kerala, Karnataka, Goa, Andhra Pradesh and by Indians living abroad (PIO) with roots in South-India such as Tamils in Malaysia, Singapore, Sri Lanka, South-Africa and other countries. The date calculation of Deepavali is based on the geographical location of Chennai (Tamil Nadu) in India. It falls on Ashvina Krishna Chaturdasi which is the lunar day before the new moon (Amavasya) in the lunisolar calendar. The exact date and time is calculated for the last 90 minutes before sunrise (Arunodaya). The 4 day festival Deepavali ends on the 2nd day in the bright half of Kartika. As the calculation is primarily based on the moon, the date of Deepavali varies in the Gregorian Calendar between the 16th October and 15th November every year. 

DIWALI Date 

Diwali is celebrated in North-India in all other states and by the majority of Indians living abroad (PIO) in countries such as USA, Canada, UK, Australia and others. Diwali is on the 15th day of the month Kartika (October/November) in the Hindu calendar - a Lunisolar calendar which is based on the positions of moon & sun - calculated for the location of Allahabad (Uttar Pradesh) in India. It falls on Amavasya (Ammavaasa), the new moon night, that ends the month of Ashwina (Ashvin/Aasho/Aswayuja) and begins the month of Kartika. The 5 day festival begins on the 13th day in the dark half of Ashwin and ends on the 2nd day in the bright half of Kartika. As the calculation is primarily based on the moon, the day of Diwali Festival varies in the Gregorian Calendar between the 17th October and 15th November every year. 

For more information on the Hindu calendar and calculation of the days of Deepavali or Diwali, please refer to Wikipedia 

 

The Indian Lunar Calendar (Diwali In The Religious Hindu Year)

Regional Names of the Days of Deepavali:

Day 1: Deepavali / Naraka Chaturdasi

Day 2: Lakshmi Puja

Day 3: Kartika Shuddha Padwa / Bali Padyami

Day 4: Yama Dvitiya

Regional Names of the Days of Diwali:

Day 1: Dhanteras / Dhantheran / Dhantrayodashi / Dhanwantari Triodasi / Yamadeepdaan / Dhan Teyras

Day 2: Choti Diwali / Kali Chaudas / Narak Chaturdashi

Day 3: Diwali / Baddi Diwali / Lakshmi Puja

Day 4: Pratipat / Padwa Puja / Gudi Padwa / Govardhan Puja / Annakoot

Day 5: Bhai Duj / Bhhaya Dooj / Bhai Beej / Dvitiya

Wed, 22 October, 2014 - Deepavali (Naraka Chaturdasi)

Thu, 23 October, 2014 - Lakshmi Pooja (Diwali)

Fri, 24 October, 2014 - Kartika Shuddha Padwa (Bali Padyami)

Sat, 25 October, 2014 - Yama Dvitiya 

Note: Diwali will fall one day AFTER Deepavali 2014 (on 23 October 2014)