Masa Shivaratri is an auspicious day to perform Shiva Puja. It falls on Krishna Paksha Chaturdashi, a day prior to Amavasya or No Moon.
Maha Shivaratri is observed on Masa Shivratri in Magh month as per Marathi, Gujarati, Telugu, and Kannada Calendars; and in Falgun month as per North Indian Hindi calendars.
Masa Shivaratri Pradosh Kaala Puja is very famous in most of the Shiva Temples such as Jyotirlinga Temples, etc.
Masik Shivaratri 2020-2021 dates..
Day, Date – Masa Shivaratri in Purnimant Calendar (North India) / Amavasyant Calendar
Thursday, 23 January 2020 – Masa Shivaratri in Magh Month / Poush Month
Friday, 21 February 2020 – Masa Shivaratri in Phalgun Month / Magh Month
Sunday, 22 March 2020 – Masa Shivaratri in Chaitra Month / Phalgun Month
Tuesday, 21 April 2020 – Masa Shivaratri in Vaishakh Month / Chaitra Month
Wednesday, 20 May 2020 – Masa Shivaratri in Jyeshta Month / Vaishakh Month
Friday, 19 June 2020 – Masa Shivaratri in Ashada Month / Jyeshta Month
Sunday, 19 July 2020 – Masa Shivaratri in Shravan Month / Ashada Month
Monday, 17 August 2020 – Masa Shivaratri in Bhadrapad Month / Shravan Month
Tuesday, 15 September 2020 – Masa Shivaratri in Adhik Ashwin Month / Bhadrapad Month
Thursday, 15 October 2020 – Masa Shivaratri in Nija Ashwin Month / Adhik Ashwin Month
Friday, 13 November 2020 – Masa Shivaratri in Kartik Month / Nija Ashwin Month
Sunday, 13 December 2020 – Masa Shivaratri in Margashirsha Month / Kartik Month
Monday, 11 January 2021 – Masa Shivaratri in Paush Month / Margashirsha Month
Wednesday, 10 February 2021 – Masa Shivaratri in Magh Month / Poush Month
Thursday, 11 March 2021 – Masa Shivaratri in Phalgun Month / Magha Month
Saturday, 10 April 2021 – Masa Shivaratri in Chaitra Month / Falguna Month