Significance
Ananta is the Energy in the form of Chaitanya that has no end. The date as per the Hindu lunar calendar (tithi) of Sri Ganesh Chaturthi is Bhadrapad Shukla Chaturthi. During the period from this tithi to Ananta Chaturdashi, the energy is emitted in higher proportion from Sri Ganeshji. The duration of Ananta vrat is fourteen years. Thereafter the vrat is concluded. This vrat is undertaken on the advice of someone or getting the thread of Ananta easily.
History
There is this tale of a little girl named Sushila, the daughter of a Brahmin, Sumant. After her mother Diksha died, Sumant married another woman called Karkash, who ill-treated Sushila. When Sushila grew up, she eloped with a young man Kaundinya to save herself the torture of her stepmother. On their way to a distant land, while Kaundinya went for a bath in the river, Sushila met a group of women who were worshiping Lord Ananta. Sushila wanted to know why they were praying Ananta and the women told her the purpose of their 14-year vow was to get rich and also achieve enlightenment.
Sushila took a cue from the women and decided to take the oath of a 14-year vow. As a result, they became wealthy. One day, when Kaundinya noticed the Anant Sutra on Sushila's left hand, he asked her about the vow. Upon hearing Sushila's story of the vow, he was angry. Kaundinya was sure that they turned rich owing to his own efforts and not as a result of any vow. A furious Kaundinya held her arm, tore the sacred thread from Sushila's wrist and threw it into the fire. No wonder, they were became very poor soon after this fiasco.
This was strong enough for Kaundinya to realize his mistake and the glory of Lord Ananta. As compensation, he decided to go through rigorous penance until Ananta himself appears before him. Despite all his adulteries, Kaundinya was not successful in seeing God. He was crestfallen, went to forest and asked the trees and the animals if they have seen Ananta. When all his effort went in vain, he prepared to hang himself and commit suicide. But he was promptly saved by a wandering hermit, who took him to a cave where Lord Vishnu appeared before Kaundinya. He advised him to observe the 14-year vow to regain his wealth. Kaundilya promised to observe the fast with all sincerity for 14 consecutive Ananta Chaturdashis, hence giving birth to the belief.
Determination of Date
Anant Chaturdashi is usually celebrated on Bhadrapad Chaturdashi covering two muhurats. If this Chaturdashi falls or does not fall on two days then it is celebrated on the first day. It is generally the tenth or eleventh day after Ganesh Chaturthi,
How to Celebrate
On this day the Visarjan of idol of Lord Ganpati (Flowing of idol in holy waters) is done in Maharashtra. All the Ganesh idols brought into homes and communities are immersed in the sea or nearby lakes and rivers. On this day, people travel to the waterfront with the idols, large and small, dancing and singing in large processions. Lord Ganesha is departed, only to be welcomed the next year with equal excitement.
In parts of Bihar and Eastern UP, the festival is closely linked to kshirsagar (Ocean of Milk) and Lord Vishnu's Anant Roopa. Fourteen tilaks(small vertical strips) of vermilion are made on a wooden plank. Fourteen puri(fried wheat bread) and fourteen pua(deep fried sweet wheat bread) are placed on these vermilion strips. A bowl containing Panchamrit (made of Milk, Curd, Jaggery, Honey and Ghee) symbolizing kshirsagar (Ocean of Milk) is placed on this wooden plank.A thread having fourteen knots, symbolizing Lord Anant is wrapped on a cucumber and is swirled five times in this "Ocean of Milk". Later this Anant thread is tied on the right arm above the elbow by men. Women tie this on their left arm. This Anant thread is removed after fourteen days.