lady Ekadasi appeared this Ekadasi is known as Uttpanna Ekadasi or Utpatti Ekadasi. Uttpanna or Utpatti means born or manifested.
Purana/Story:................................
Yudhistira: What is the origin of Ekadashi? How did this day become the most important day in the world? Why do everyone including all gods prefer this day? Pray please tell Sri krishna.
Sri Krishna: in Krtayug there was an Asura named Mura. he was so strong that he defeated all the gods including Indra and chased them out of the heaven. Devandra ran to Mt. Kailash and appealed to Rudra devaru, who directed Indra to go seek solace with Sri Hari.
devendra, went to vaikunta and appealed to Sri Hari to save the world. He said O Sri Hari the son of tAlajangha Murasura, has conqured the heavens. He is ruling the world with an iron hand from his capital chandravati. Please save us.
So Sri Hari along with the Devas went to chandravti to fight the Asura. Sri Hari destroyed the Asura army with his Sudarshan chakra. However Mura fought valiantly and they fought a duel for years. All the devas were scared and ran away. Sri Hari too ( in his leela ) got tired and decided to rest near badrikashrama in cave named simhapati.
Asura Mura followed him there and seeing Sri Hari taking rest, the Asura was overjoyed and rushed at Sri Hari to kill him. Suddenly from the body of Sri Hari rose a wonderful Goddess. Born with all the charisma and radiance of Sri Hari she had a heavnly weapon in her arms. She asked the Asura to fight with her. Murasura accepted, he rushed at her to kill her. However the goddess was so powerful, just her war cry destroyed the Asura. He was burnt to ashes. Sri Hari woke up just in time and inquired as to who killed his enemy and came to his rescue.
Goddess: It was I who killed this Asura.
Sri Hari: This Asura was so powerful, even I couldn't defeat him. How did you do it.
Goddess: It was all because of your grace. You did this for the benefit of the world. It was only through your grace I was able to defeat Murasura.
Sri Hari: The whole world is very joyous for what you did, please ask for any boons.
Goddess: Please grant me three boons.
1. I should be the most prominant of all the thithis ( days )
2. I should be the destroyer of everyone's obstacles
3. I should be grantor of wishes.
Whoever fasts in my name, worshiping you with devotion, should be granted all their wishes. on dashmi who eats once ( ekabhukta or naktha ), fast on ekadashi and parane on Dwadashi, please grant their wishes.
Sri Hari: So be it. all the 12 months, especially in the month of karthika, whoever does ekadashi vrat and worships me, will attain moksh. tritiya, ashtami, navami and chaturdashi thithis are dear to me. However ekadashi thithi is the most dearest to me.
Thus the goddess, who was born from Sri Hari's radiance, who saved his life, is the abhimani devata for Ekadashi vrat. It is she who with Sri hari grace will rid of all the sins and grant all the wishes for those who fast on Ekadashi.
Rules for Observing Ekadasi Fast