Mahashivratri (with “Shivratri” also spelled as Shivaratri, Shivaratri, Shivaratri, Shivarathri or Shivarathri) is also held because the night when Lord Shiva executed the Tandava Nritya, the dance of primordial advent, maintenance and destruction. at the night time of Mahashivratri, there's a natural upsurge of strength that promotes non secular evolution.