The marriage of Shiva Parvati or Shiva Sati did not take place on the day of Mahashivratri.
Let us see from Shiv Purana-:
Regarding the marriage of Shiva and Bhagwati Sati, in the Sati section of Rudra Samhita of Shiv Purana, in chapter number 18, verse number 20 and
The following words are found in verse number 38 in chapter number 20 of Rudra Samhita Sati Khand.
1) On Sunday, in Trayodashi of Shukla Paksha of Chaitra month, in Purva Phalguni Nakshatra, Lord Maheshwari performed the journey for marriage and completed the marriage ceremony.
(Rudra Samhita Sati Khand Shiv Mahapuran)
Now let us see what Shiv Purana says about the marriage date of Lord Shankar and Mother Parvati.
In verse number 58 to 60 of chapter number 35 of the mountain section of Rudra Samhita of Shiva Purana.
Vashishtha ji tells Himalaya ji that:
After a week, a rare and auspicious yoga is coming, in that ascendant, the lord of the ascendant is situated in its own house and the Moon will also be positioned with its son Buddha. Moon will be with Rohini, it is the month of Margashirsha.
It is Monday.
In this auspicious yoga, you should dedicate your daughter to Lord Shiva.
(Shiv Mahapuran Rudra Samhita Parvati section)
Both these evidences prove that Lord Shiva’s marriage did not take place on the day of Shivratri because Shivratri falls in the month of Phalgun.
So let us know what actually happened on the day of Mahashivratri. We know why it is called Mahashivratri and why it is so important, the answer to this is also given in Shiva Mahapuran itself.
Vidyeshwar Samhita of Shiva Mahapuran
According to Chapter No. 8, on the day of Mahashivratri, Lord Shankar first showed his physical form to Brahma and Vishnu and became formless from formless and appeared in the form of Shivalinga.
Therefore, Shivratri is celebrated on this day and Shiva is worshipped.
Eternal best wishes on Kalratri Mahashivratri, the most sacred festival of manifestation of Adipurush, Aadiyogi, Jagadguru, Jagadish, but Brahma Parmeshwar Devadhidev Mahadev Shiv Shambhu in the form of light symbol (Jyotirlinga).
har har mahaadev