About Shani Dev :
As per Ancient Vedic Texts, Saturn is a Cruel planet. Astrologically, it is said that planet Saturn is a judge of our past deeds. The planet Saturn is a natural benefactor of jobs and services, metals, industries, age, poverty, hardships, diseases, all kinds of obstacles and selfishness. A person having weak or a malefic Saturn in his horoscope has to undergo sufferings in all his life and his progress is very slow even with a very hard work. However, if the planet Saturn is favourable in a person's horoscope then he can get very good Success, Name and Fame in his Business / Career especially in those areas that are governed by Saturn like Industries. When Saturn is adverse, it causes many problems, accidents, conflicts, poor financial position, sorrow, sadness, depression, poverty etc. Under such circumstances, a Shani Puja or Yantra can bring peace and comfort. People also perform Navgraha Shanti Puja to the best of their abilities on Shani Jayanti to please planet Saturn. Large number of devotees are seen thronging at Shani Temples in order to ensure that Good Luck favours them.
If the planet Saturn is in conjunction with planet Rahu, then it forms a bad yoga known as " Shani Rahu Shrapit Dosha " which adversely affects almost all the areas of life and the person's life is full of hardships. Similarly, if the planet Saturn is in conjunction with planet Moon, then it forms another bad yoga known as " Shani Chandra Vish Yoga ". Such a person is very intelligent, yet at times he can fall prey to extreme negativity and depression. In all such cases, worshipping a Shani Yantra can be extremely beneficial.
A person is said to be under the major affliction of Saturn known as "Saturn Sade Sati" when the planet Saturn is transiting through the 12th, 1st and 2nd house from the Natal Chart Moon, each transit being of approximately two and a half years. A person has to undergo all kinds of hardships during this period including stress, anxiety, tensions, loss of mental peace as well as financial losses. These problems are more profound if the planet Saturn is malefic in his horoscope.
Similarly, a person is said to be under the minor affliction of Saturn known as "Small Panoti" when the planet Saturn is transiting through the 4th or 8th house from his Natal Chart Moon. The adverse effects of Small Panoti are also similar to Saturn Sade Sati. In both these afflictions also, worship of Lord Shani can provide an immense relief.
Prayers for Shani Dev to prevent Evil Spirits :
Some people are known to observe fast on Shani Jayanti in order to ensure that they are able to lead an easy and hurdle free life. The processes and events that follow to fasting are similar to that of Shanivar Vrat or Saturday Fast. However, learning about the process associated with the observation of fast in an accurate manner is something that is needed the most. People across India are known to perform Shani Vrat to ensure that their personal life is protected to the core besides their families and relatives. It is advisable to perform Shani Mantra Japa 11000 times or 23000 times in order to maintain a peaceful and prosperous life. Offering special poojas in this context are certainly helpful in changing the position through which your fortunes too could be changed accordingly.
On Shani Jayanti, devotees perform ‘Shani Shanti puja’. Shani homam or yagya are also conducted by the people in the presence of acharya or purohit to protect themselves from all wrongs and black magic. To avoid witchcraft, people wear horse shoe rings in their fingers and also hang the horse shoes in their houses. It is commonly believed that Lord Shani creates hindrance in one’s growth. Hence, in order to delight Lord Shani, the following mantra can be chanted regularly :
" Om Praang Preeng Praung Sah Shanishcharaya Namah "
Shani Jayanti has lot of significance of its own in the Indian culture. People strongly believe that by worshipping Lord Saturn, all the hurdles and problems in one’s path are eliminated. It is considered very essential to get free of Shani Dosha before starting a new venture.