Why Kari Naal (Selected Days) Are Considered as Inauspicious Days?

Kari Naal is generally considered as an inauspicious day in the State of Tamil Nadu, India. All Tamil Hindus will avoid all days marked as Kari naal. There will no functions like marriiage, upanayanam, seemnadham, house warming ceremony etc. Also death on a particular kari naal day is considered as inauspicious and the purohits recommend special remedies to mitigate the dosha.. To be more specific there will be kari naal in each Tamil solar month. Kari naal is identified on the basis of a particular tithi meeting particular constellation or star on a particular week day. The Tamil astrology and almanacs mark 33 days in a solar (calendar) year as Kari naal. It is believed as local practice. The scholars of Tamil astrology say that there is no evidence about Kari Naal in the classic texts of Vedic Hindu astrology. The following table lists kari naal against each Tamil solar month:

1) Mesha, (Chithirai), mid-April to mid-May - (Two days) 6th and 15th of this month.

2) Rishabha, (Vaikasi) mid-May to mid-June - (Three days) 7th ,16th and 17th of this month.

3) Mithuna, (Aani) mid-June to mid-July - (Two days) 1st and 6th days of this month.

4) Karkataka (Aadi) mid-July to mid-August - (Three days) 2nd ,10th and 20th of this month.

5) Simha (Aavani) mid-August to mid-September - (Three days) 2nd ,9th and 28th of this month.

6) Kanya (Puratasi) mid-September to mid-October - (Two days) 16th and 29th of this month.

7) Tula (Aippasi) mid-October to mid-November - (Two days) 6th and 20th of this month.

8) Vrischika (Karthikai) mid-November to mid-December - (Three days) 1st ,10th and 17th of this month.

9) Dhanu (Markazhi) mid-December to mid-January Dhanu - (Three days) 6th ,9th and 11th of this month.

10) Makara (Thai) mid-January to mid-February - (five days) 1st, 2nd, 3rd, 11th, and 17th of this month.

11) Kumbha (Masi) mid-February to mid-March - (Three days) 15th,16th and 17th of this month.

12) Meena (Pankuni), , mid-March to mid-April - (Three days) 6th, 15th and 19th of this month.

Reference

http://ramaswamysastry.blogspot.com/2010/07/kari-naal-agni-nakshatra-panchak.html
http://in.answers.yahoo.com/question/index?qid=20100727083912AAbyVsA