Devotees intending to go on Sabarimala pilgrimage are to observe vratha (austerity) for 41 days for darsanam during the Mandala puja at Sabarimala. Mandala pooja means pooja done for the period of a Mandala. A Mandala is of 41 days. Normally Sabarimala temple is open only for 5 days from the 1st of each of the Malayalam calendar months. Apart from these poojas there will be occasions like the major festivals of Kerala when puja is conducted during the festival period. The only occasion when the temple is open continuously for a long period of days is during the Mandala puja. This year the Mandala puja culminates on the 27th of December. Then again the temple will open after a few days for the most important occasion of the temple, the Makara Vilakku. For Sabarimala the Mandala period starts on the 1st day of Malayalam month Vrishcikam (generally falls at the beginning of the 2nd half of November) till around the 25th to 27th of December. The vrathas starts with the devotee putting on the Thulasi Mala or Rudraksha Mala with a dollar of Lord Ayyappan in it. After wearing the Mala the most important aspects of the vratha is the strict adherence to abstinence, avoiding all sorts of sensual pleasures, maintaining extreme purification of body and mind of the devotees. They have dress code to observe so that they are identified as the Ayyappan devotees and others take care not to do things which may interfere with the purification process of the devotees.
The daily routines prescribed include getting up early in the morning and finishing the morning routines and take bath. After bathing they are to apply the sacred ash and sandal paste on forehead and do pooja to the Lord and other family deities. It may take around 1 hour time. In the evening too they have to take bath and pray like in the morning. The devotees after starting the vratha are called as Ayyappans or swami. They are not to use non vegetarian eatables, tobacco and liquor during the period of the Mandala vratha observance. This period may be 41 days or 56 days depending on the individual pilgrim concerned. Many of the devotees observe the code for 41 days and go to Sabarimala for darsanam after the observance of the austerity. The Mandala Pooja at the Sabarimala temple is done on the 41st day. This year it is on the 27th December, 2011. Throughout the period from 1st Vrishcikam to the Manadala puja day and then for the Makara vilakku period which is around 14th January devotees come in thousands for darsanam of the Lord to Sabarimala. In between the Mandala puja and the Makara vilakku puja some of the days the temple will be closed.
Some people observe the vrathas till the 1st of Makaram month of Malayalam calendar. The Makara sankranthi day normally on 14th January (1st of Makaram – transition from Dhanu month to Makaram), the start of Utharayana kaalam (Sun's journey towards north) is the most auspicious day at Sabarimala and the next most important day is the Mandala puja day normally falls in the 4th week of December. Since recently the temple is open to devotees on the 1st to 5th of each of the Malayalam months and other important festivals days of Kerala like the 'Vishu' (Malayalam New year day – usually on April 14th) and Thiru Onam etc. However as per the conditions of the pilgrimage, devotees are to observe 41 days austerity - vrahta.