A comparative study of tri-diurnal anisotropy of Cosmic Ray intensity data has been performed for Deep River neutron monitoring station on geo magnetically 60 quietest days, 120 quiet days and all days during 1992-94. Histographic plots of percentage of occurrence of days for Phase (hrs) in a definite interval reveals that Phase is maximum in the interval of 0 to 2 hrs directions during the year 1992-93. Whereas it is maximum in the interval of 0 to 3 hrs directions for the year 1994. However, the value of peak relative to its neighbors is quite large in case of quietest days. The peak sharpening is equally noticeable in case of amplitude histograms as well. This bring out the fact that five most quietest days for study of daily variation on long term basis as well as short term basis. These results clearly indicate that the behavior of Sixty quietest days are most suitable for an-isotropic studies on long / short term basis. The time / spatial variation in the amplitude and phase tri-diurnal anisotropy becomes more pronounced for sixty quietest days.