Dhanur Sankranti, also known as Dhanu Sankramanam, is the transition of the Sun to Dhanu Rashi or the zodiac sign of Sagittarius. In 2009, Dhanu Sankranti date is December 16. Usually, Dhanu Sankraman occurs on Margasira Amavasya as per Telugu and Kannada calendars. As per Tamil calendar, Dhanus sankraman falls on the first day of Margazhi or Margali masam (Margazhi Amavasi).
Dhanur Sankraman marks the beginning of Dhanur Masam in Andhra Pradesh and some parts of Karnataka. Dhanurmasam is the most auspicious period for Vaishnava sect of Hindus. Pavai Nombu begins on Dhanur Sankraman day in Tamil Nadu and Kerala.
Pavai Nombu 2009 – Margazhi Nombu or Margali Nombu
Dhanu Sankranti – Dhanu Sankranthi
Dhanurmasam 2009–2010 - Dhanumasm
Prathamashtami 2009 – Prathamastami Festival in Orissa
Subramanya Sashti 2009 – Subrahmanya Shashti

[...] Dhanu Sankranti 2009 – December 16 [...]
[...] This month is the most auspicious month the devotees who Vaishnava tradition. Dhanurmasam begins on Dhanur Sankramanam day. On this day Sun enters into Dhanu Rashi (Sagittarius zodiac [...]