In a Horoscope when Saturn (Shani) in transit enters the 8th house from house occupied by Moon then the native is termed as under Shani ki Dhaiya.
There is a general myth that these 2.5 years is a very bad time for the native.
It is totally a myth, we have to first calculate what is the position of Moon and Saturn in the ascendant chart i.e. which house they have occupied, they are lord of which houses and in which constellation and sub-constellation they are placed. It is also important to see deeply the other planets which are in any type of connection with Saturn and Moon. This should be deeply analyzed then we can predict whether its result would be good or bad.