Onam is not a celebration of a one day or two days. Onam is a grand gala of 10 festive days. In 2009, Onam festival celebrations begin on August 24 and ends with Thiru Onam on September 2. Onam calendar consists of 10 festivals celebrated from day one – Atham – till the 10th and final day – Thiru Onam.
Atham festival – First day – 24 August, 2009
Chithira – Second day – 25 August, 2009
Chodhi – Third day – 26 August, 2009
Visakam – Fourth day – 27 August, 2009
Anizham – Fifth day – 28 August, 2009
Thriketa – Sixth day – 29 August, 2009
Moolam – Seventh day – 30 August, 2009
Pooradam – Eighth day – 31 August, 2009
Uthradam – Ninth day – 1 September, 2009
Thiruvonam – Tenth day – 2 September, 2009
Batukamma 2010 - Batukamma Festival date in 2010
Kanya Puja - Worship of Young Girls During Durga Navratri
Durga Nimajjan - Durga Idol Immersion after Durga Navratri
Bhai Dooj 2010 - Bhai Dhuj Bhau Beej or Bhai Dhooj in 2010

This is the actual days of celebration.
This year there will be 11 days as the Thriketa extends to 27th as well 28th
Atham festival – First day – 23 August, 2009
Chithira – Second day – 24 August, 2009
Chodhi – Third day – 25 August, 2009
Visakam – Fourth day – 26 August, 2009
Anizam – Fifth day – 27 August, 2009
Thriketa – Sixth day – 28 August, 2009
Thriketa – Sixth day – 29 August, 2009
Moolam – Seventh day – 30 August, 2009
Pooradam – Eighth day – 31 August, 2009
Uthradam – Ninth day – 1 September, 2009
Thiruvonam – Tenth day – 2 September, 2009