Karthika Somavaram Vratham (Mondays in Karthik Month) are highly auspicious as per Telugu panchangam and Kannada calendar. In 2017, Karthika Somavaram vratham dates are: October 23, October 30, November 6 and November 13.
There is Koti Somavaram in 2017 – October 28. In some areas, any day of Saptami which coincides with Shravana Nakshatra, before Kartik Purnima is also considered highly auspicious as Koti Somavaram and sometimes also referred to as Koti Somavaram.
In some parts of Gujarat and Maharashtra also, Karthika Somvar Vrata is observed with utmost gusto.
As per the North Indian calendars and beliefs, Kartik Month is dedicated to Lord Vishnu and Goddess Lakshmi. Lakshmi Puja and Vishnu puja are observed throughout the month in some communities in North India. But, according to South Indian beliefs Kartik Month is dedicated to Lord Shiva also and the Mondays in this month considered highly auspicious.
Telugu and Kannada people celebrate Karthika Somavara Vratam by visiting Shiva temples, performing punya snana in holy rivers such as Godavari, Krishna, Tungabhadra, Cauvery.
In North India, the similar puja and vratha are observed on Shravan Somvar days (Mondays in Shravan Month).
In 2016, Karthika Somavaram vratham dates – October 31, November 7, November 14, November 21 and November 28. There is Koti Somavaram in 2016 – November 7.