This year's Rashtriya Panchang, which has been issued by the Central government in 14 different languages, shows February 14, as Maha Shivaratri. The festival’s auspicious time is only for few hours starting from the night of Tuesday, February 13.
According to Hindu mythology, Maha Shivaratri — the festival marks the night when Lord Shiva danced the Tandava and destroyed the enemies. Lord Shiva is considered to be supreme, Paramaatman, Brahman and ‘the absolute’ destroyer and re-producer of life.
Going by some other religious scriptures it is also learnt that, Lord Shiva married Goddess Parvati on this day.
The Hindu calender has put the Shivaratri on the chaturdashi tithi during Krishna Paksha in the month of 'Magha.' The North Indian calender varies with respect to the date and timing where Masik Shivaratri in month of Phalguna is known as Maha Shivaratri.
In both the calenders the only thing that matters or differs in other word is naming convention of lunar month. However Maha Shivaratri is celebrated on same day by both North Indians and South Indians.
Maha Shivaratri Muhurta:
On 14th, Maha Shivaratri Parana Time = 07:04 to 15:20
Ratri First Prahar Puja Time = 18:05 to 21:20
Ratri Second Prahar Puja Time = 21:20 to 24:35+
Ratri Third Prahar Puja Time = 24:35+ to 27:49+
Ratri Fourth Prahar Puja Time = 27:49+ to 31:04+