Vaikuntha Ekadashi falls during Dhanur solar month in Hindu calendar. Dhanur month or Dhanurmasa is known as Margazhi month in Tamil Calendar. Vaikuntha Ekadashi is Shukla Paksha Ekadashi out of two Krishna Paksha and Shukla Paksha Ekadashis in a month. Vaikuntha Ekadashi is observed according to Solar Calendar and because of that it might fall either in Margashirsha or in Pausha month in Hindu Lunar calendar. In Gregorian calendar there might be none, one or two Vaikuntha Ekadashis in a year.
Benefits - Vaikuntha Ekadashi is also known as Mukkoti Ekadashi. It is believed that Vaikuntha Dwaram or the gate of Lord's inner sanctum is opened on this day and devotees who observe fast on Vaikuntha Ekadashi attain salvation by going to Heaven.
Vaikuntha Ekadashi is very important day for Tirumala Venkateswara Temple at Tirupati and Sri Ranganathaswamy Temple at Srirangam.
Vaikuntha Ekadashi is known as Swarga Vathil Ekadashi in Malayalam Calendar followed by people of Kerala.
Parana means breaking the fast. Ekadashi Parana is done after sunrise on next day of Ekadashi fast. It is necessary to do Parana within Dwadashi Tithi unless Dwadashi is over before sunrise. Not doing Parana within Dwadashi is similar to an offence.
Parana should not be done during Hari Vasara. One should wait for Hari Vasara to get over before breaking the fast. Hari Vasara is first one fourth duration of Dwadashi Tithi. The most preferred time to break the fast is Pratahkal. One should avoid breaking the fast during Madhyahna. If due to some reasons one is not able to break the fast during Pratahkal then one should do it after Madhyahna.
At times Ekadashi fasting is suggested on two consecutive days. It is advised that Smartha with family should observe fasting on first day only. The alternate Ekadashi fasting, which is the second one, is suggested for Sanyasis, widows and for those who want Moksha. When alternate Ekadashi fasting is suggested for Smartha it coincides with Vaishnava Ekadashi fasting day.
Ekadashi fasting on both days is suggested for staunch devotees who seek for love and affection of Lord Vishnu.