Three Brahmotsavas are celebrated in the months of Chithirai (VirupPan tirunaal), Thai (Bhupati tirunaal), and Panguni (Adibrahmotsavam).
Festivals may be classified into Parvotsavas, Ekadinotsavas, Masotsavas, and Brahmot savas. Parvotsavas are simple festivals celebrated within the temple on the five following occasions or pancaparvas each month: 1. masa sankramanam or the commencement of every month, 2. amavasya, 3. paurnami, 4. and 5. the two ekadasis in each month. In addition, parvotsava is celebrated on the day of Revathi, the natal star of God Ranganatha.
On all these occasions, the utsava image is brought out of the sanctum into the mahamandapa, taken down the western steps into the first or Rajamahendran enclosure, where He is taken in Procession pradakshina wise and brought back to the mandapa through the eastern steps.
The ceremony of ascending the steps is called padiyetram and is done to appropriate music by the arayars. Then He is restored to His position in the sanctum. When bigger festivals are celebrated, the parvotsavas get merged with them.
The ekadinotsavas or single day festivals such as Chitra Paurnami, Jyeshtabhisekam, Pathinettam perukku (Adi l8th), Sri Jayanthi, Vijayadasami, Deepavali, Karthikai dipam, Sankaranti and Yugadi last for a day.
The monthly mahotsavas and the annual brahmotsavas Iast for more than a day, usually about ten days. The important mahotsavas are the puchuthu tirunal or the flower festival (Dhavanotsava) in Chithirai, also called Kodai tirunal when the deities are specially decorated with flowers of the month, roughly corresponding to April, marking the beginning of the flowering season.
Vasantotsava is celebrated in Vaikasi, Jyeshtabhisekamin Ani, Pavitrotsavam in Avani, Navarathri in Purattasi, rvhich is celebrated solely for the Goddess, Sriranba Nachiyar, Dolotsavam or swing festival in Aippasi, Vedaparayana Tirunaal or Adyayanotsavam, which lasts for 22 days in the month of Margazhi, and the Float festival in Maasi. It is the practice that all functions and processions of the masotsavas are conclusion festival. conducted in the evenings.
Three Brahmotsavas are celebrated in the months of Chithirai (ViruPpan tirunaal), Thai (BhuPati tirunaal), and Panguni (Adibrahmotsavam). The distinguishing marks of a Brahmotsava are its commencement with Dwajarohanam or the hoisting of the flag on the flagstaff and its with Rathotsavam or car festival.
Chithirai month’s Festivals (Apr - May)
car festival is celebrated and it is called “chithirai ther” , huge amount of people from all overindia , particularly huge number of village people pull the big rope of the car. It is enormous car for lord sriranganathar.
Vaikasi Month’s Festivals (May - Jun)
The spring month festival is called vasanthotsavam, celebrated for nine days prior to the vaikasi month full Moon day(pournami). This Festival is celebrated in the backyard which is situated to the north side of the chakarathalvar sanathi. The place which is around the pool full of water and lotus flower, the center of the pool sriranganathar is placed like a king of heaven.
Aani month’s Festivals (Jun-July)
On the Aani month Jestabisegam for sriranganathar , the holy water taken in gold pots from the rivers “cauvery” is used for thiru manjanam(same as” abishagam”) at big sannathi, next day the maha naivaden(offering to the god) is contributed by large amount of cooked rice(called “thiruppavadai”), after the rice is distributed to the devotees as a prasadam
Aadi month’s Festivals (July-Aug)
This month Aadi 18 is celebrated on banks of river Cauvery, Aadi 18 is one of the famous tamil festival of tamilnadu. In this day lord sri renganatha submitted flower ring and other ornaments to Cauvery at Amma Mandapam. People will float a lamp with money to the Cauvery water.
Avani month’s Festivals (Aug-Sep)
Pavithrotsavam is famous for nine days festival celebration subsequent of Sri krishna jayanthi is celebrated. Uri-Adi(a pot filled with turmeric water is balanced over a rope. and the milk grocer community people(konar) ,after closed their eyes by the yellow cotton cloth .use to hit it. This is a ceremony which remembers that lord Krishna also belonged to that community) takes place at the south gate near Pathala(underneath) Krishna Temple.
Puratasi Month’s Festivals (Sep-Oct)
This month Navarathri is celebrated Nava(9) Rathiri(night time) this festival is famous among the teen age girls ladies and children. Temple Utsava takes place at Sri Renga Nachiyar Sannathi. The Elephant called ‘andal’ will play events like dancing with one leg lifted and plays mouthorgan. Sri renganatha goes to Kattu Alagia Singaperumal koil in honor of Killing Vaniyasura and comes out in the Horse Vahana.
Aipasi Month’s Festivals (Oct-Nov)
Unjal Utsavam also celebrated by 9 days in this month. In this whole month the holy water from river cauvery will be taken for renganathar’s abishegam (holy bath) using golden pot , silver pot and copper pot for the security reason copper pot is used here.
Karthikai Month’s Festivals (Nov-Dec)
Karthikai is celebrated all over tamil nadu as a light festival (array of small lamps inside and out side the house in a beautiful fleet) is celebrated also srirangam temple in big manner by next day of thiruvanamalai Karthikai festival. Pearumal takes a special thirumanjanam and comes out through the streets of srirangam in a wagon decorated with attractive flowers. Blaze-fire or chockpanai is the important festival at the end of the day after perumal hears the annual account read by kanakku pillai(treasurer).
Margali Month’s Festivals (Dec-Jan)
The important festival of this month is the presentation of thiru pavai poem (composed by “Andal” a girl devotee and she loved by lord sriranganatha ). after that the vaikunda ekadasi festival in which sriranganatha use to be seen in dasavathara alangaram (representing the ten incarnations “avatars” of the lord Vishnu).
Thai Month’s Festivals (Jan-Feb)
The thai pongal known as “Tamilar thirunal” celebrated in first day of the month ” bogi pandigai” is celebrated on perivious day of the pongal concept of the festival is to destroy the old thoughts and things . Thai car festival is the important festival of this month for sirangam temple.
Masi Month’s Festivals (Feb-March)
Theppotsava which is a Festival where lord perumal is floated on a theppam (boat) in the pool situated to the west side of the temple.
Panguni Month's Festivals (March-Apr)
Adhi brahmotsava is celebrated in this month and also kept the panguni uthra day. Subsequently lord gladden the chariot festival (called as “Rathasaptami”).
Book Ref: srirangam temple calendar 2009.