Apara

http://harekrishnacalendar.com/vaishnava-calendar/apara-ekadashi 

Procedure

1. Apara Ekadashi Vrat begins from sunrise and continues till the sunrise of the next day. 
2. After completing all the basic activities of the day, take bath and wear clean clothes.
3. Offer prayers to Lord Vishnu with a clear mind, heart, and soul. Please the Lord with offering of Tulsi leaves and fresh fruits on Apara Ekadasi.
4. While observing Apara Ekadashi Vrat, avoid intake of grains, non-vegetarian food, and alcohol.
5. If you are observing a partial fast, you can rely on intake of fresh fruits, nuts, and milk.
6. Spend entire day of Apara Ekadasi in devotion of the Lord and chanting Mantras.
7. Break your Vrat on the next morning after taking bath and worshiping Lord Vishnu.

Benefits

achieve merits equivalent to the below mentioned religious deeds (Karmas):

• Holy bath taken in Prayaga during the month of Magha
• Offering Tarpan or satisfying the soul of forefathers at Gaya
• Donating elephant, cow, gold, clothes, etc. as charity
• Taking holy bath thrice in Pushkar during Kartika Masa
• Offering prayers to Lord Shiva in Varanasi on the eve of Shivratri

- See more at: http://www.mykundali.com/festival/ekadashi/aparaekadashi.asp#sthash.5XsxkuA8.dpuf

Names

1. Apara Ekadashi or 
2. Achala Ekadasi or 
3. Vaisakha Vadi Ekadasi, 
4. In northern regions, like 
1. Punjab, 
2. Haryana and 
3. Places of Jammu and Kashmir, the ritual is known as Bhadrakali Ekadashi - the Birthday of Kali and is considered one of the most propitious days for worshipping Goddess Bhadra Kali.
5. On the other hand in Orissa, this vrat is referred to as Jalakrida Ekadashi, which is dedicated to Lord Jagannath in Puri.