Dussehra is celebrated on the day when Dashami Tithi (10th date) of the Shukla Paksha (bright fortnight) of Ashwin month is prevalent during the Aparahan Kaal. The festival is celebrated to remark the wining of good over evil because on this day, God Rama had killed Ravan. At some places, the festival is also known as Vijayadashami, as it is assumed to be associated with the Goddess Vijaya. Some people also know this festival as Ayudha pooja.

About Dussehra Muhurat

1. Dussehra is celebrated on the Ashwin Shukla Dashami during Aparahan Kaal. This Kaal is the duration of the time period which begins from the 10th Muhurat after sunrise and ends before the 12th Muhurat.
2. If Dashami is prevalent for two days and Aparahan Kaal is being covered only during the second day, Dussehra will be celebrated on the 2nd day only.
3. If Dashami is prevalent during the Aparahan Kaal of 2 days, Dussehra will be celebrated on the 1st day only.
4. If Dashami is prevalent through the two days but not in the Aparahan Kaal of any day, Dussehra festival will be celebrated on the 1st day.

Shravan Nakshatra also affects the Muhurat of Dussehra. The logics are given below:

1. If Dashami is prevalent through the two days (whether in Aparahan Kaal or not), but Shravan Nakshatra is prevailing through the Aparahan Kaal of the first day only, Vijayadashami will be celebrated on the 1st day.
2. If Dashami is prevalent through the two days (whether in Aparahan Kaal or not), but Shravan Nakshatra is prevailing through the Aparahan Kaal of the 2nd day only, Vijayadashami will be celebrated on the 2nd day.
3. If Dashami Tithi is prevalent for two days, but Aparahan Kaal is being covered on the 1st day only, Dashami is running till the first 3 Muhurats of the 2nd day, and Shravan Nakshatra is prevalent during the Aparahan Kaal of the 2nd day; in this condition, Dussehra celebration will be held on the 2nd day.
4. If Dashami is prevalent through the Aparahan of 1st day and till the less than three Muhurats of 2nd day, Vijaya Dashami will be celebrated on the 1st day rejecting all other conditions of Shravan Nakshatra.

Dussehra Puja & Celebration

Aparajita Puja is performing during Aparahan Kaal. The pooja Vidhi is given below:

1. Find a pious and favorable place to worship in the Northeast way from your home. It can be the vicinity of a temple, garden, etc. It will be great if the whole family can be involved in the Pooja. However, individuals may also do it alone. 
2. Clean the area and make Ashtadal Chakra (the ring of eight lotus petals) with Sandalwood paste.
3. Now, take Sankalp that you are performing this Pooja of Goddess Aparajita for the welfare of your family and yourself.
4. After that, invoke Goddess Aparajita in the centre of the Chakra with this Mantra: अपराजिताय नमः
5. Now, on her right invoke Goddess Jaya with the Mantra: क्रियाशक्त्यै नमः
6. On her left, invoke Goddess Vijaya with the Mantra: उमायै नमः
7. After that, do Shodashopchar Pooja with the name Mantras: अपराजिताय नमः, जयायै नमः, विजयायै नमः
8. Now, pray - O Goddess, I have perform the Pooja rituals as per my skill, kindly accept it before departing.
9. As the Pooja is over now, do Namaskar.
10. Do Visarjan with the Mantra: हारेण तु विचित्रेण भास्वत्कनकमेखला। अपराजिता भद्ररता करोतु विजयं मम।

Aparajita Pooja is the main part of Vijay Dashmi for the worshippers. However, there is some other worship that is done on this day; check them below:

1. When sun sets and few stars get visible, this period is called Vijaya Muhurat. In this term, any Puja or work can be initiated for the best results. God Rama had beaten the King of Lanka, Ravana by starting his journey for the war in this Muhurat. At this time only, a Shami tree had taken the bow of Arjuna (this bow was named Gandiva) to keep it safe.
2. Dussehra day is considering one among the most favorable days of the year. It is one of the Sadhe Teen Muhurats (three and a half most favorable Muhurats of the year - Ashvin Shukla Dashami, Chaitra Shukla Pratipada, Vaishakh Shukla Tritiya, and Kartik Shukla Pratipada (half Muhurat)). The entire day is considered favorable for start or doing anything. However, certain Muhurats can be considering for some particular Poojas.
3. Kshatriyas, warriors, and soldiers worship their weapons, which are known as Ayudh Puja. They also do Shami Poojan. In the old days of Kingship, this festival was mainly considered for the Kshatriyas (royals and warriors).
4. Brahmins worship Goddess Saraswati.
5. Vaishya worships their ledgers.
6. Navratri Ramlila, which is organised at many places, comes to an end.
7. Victory of God Rama is celebrated by setting ablaze the effigies of Ravana, Kumbhakarna, and Meghnad.
8. It is assumed that reciting the ‘Aparajita Stotra’ of Bhagwati Jagdamba on this day is very fortunate.
9. In Bengal, the grand Durga festival is concluded.

Dussehra Legend

As per the beliefs, the festival got its name Dussehra because on this day, God Rama had killed the ten-headed (Das Saar) devil, Ravana. Since then, the ten heads of Ravana effigies are burnt considering each of them as the expression of lust, greed, anger, delusion, envy, intoxication, selfishness, inhumanity, injustice, and ego.

Duryodhan had defeated Pandavas in the game of gamble. As promised already, Pandavas had to go for 12 years of exile along with an extra year of hidden life. In that last one year, they had to stay hidden from everybody and if found by anyone, they would repeat their 12 years of exile. For that one year, Arjuna had hidden his bow, Gandiva on a Shami tree and worked for King Viraat with the fake character of Brihannala. When the son of the King asked Arjuna to help him in protecting the cows, Arjuna brought back his bow from the Shami tree and defeated the opponent.

Another legend states that when God Rama began his journey toward Lanka for the war, Shami tree had announced the wining of the Lord.

If you want to relish the real taste of this festival, visit Mysore. The Mysore Dussehra Festival is famed for its grand celebration. From the day of Dussehra only, people accelerate their arrangements for the Diwali festival.

With this information, we hope that you will be able to make the best out of this day.