It takes 30 years for Saturn or Sani to complete its travel along the full zodiac signs and it stays for 2.5 years in each House in the Horoscope. That is it stays in the house of Aries or Mesham for two and a half years and then transits to the house of Taurus or Rishabha at the end of this period and then moves on to the next house and so on.
The transit from one house to the other becomes very significant in that the house position of Saturn will vary for individuals thus affecting the area that Saturn rules.
Click on the year you are interested in to find the Sani Peyarchi or Saturn transit details for that particular year. You can find out the dates when Sani Peyarchi takes place and the houses involved in the same for the year.