Har Har Mahadev!
Mahashivratri is the day when the Shiva tattva touches the earth. The consciousness, the aura or the ethereal world, which is always 10 inches above the material ground, touches the earth element on the day of Mahashivratri. It is the wedding of the material with the spiritual, and that is the celebration. Shiva is the soul (of everything) - there is no difference between the soul and Shiva. Your true nature is Shiva, and Shiva is peace, infinity, beauty, and the non-dual one. Ratri means'to take refuge', Shivratri is taking refuge in one's own spirit (Shiva). It is the day that we celebrate soul or spirit ( Shiva Tattva) within ourselves. Ratri which translates as 'night' is that which gives you rest, or peace. Three types of peace needed:
3. Peace of the soul
If there is disturbance around you, you cannot be peaceful. You need peace in your environment. You also need peace in the body and mind, and you need peace in the soul.
At SSDS, Nairobi, the devotees conduct Abhishek the entire day, offering milk, water and Bil patra (leaves), and get immense blessings from Lord Shiva. So, Shivratri is the celebration of Nature rejoicing the presence of benevolence, truth and beauty. Har Har Mahadev!