The sun pillar on the eighth day of October 1986 was Jiazi, and the corresponding five-element attribute was wood. Therefore, the five-element attribute of the eighth day of October 1986, which was in the year of Tiger, was Wood.
It should be noted that the five-element attributes are only a method of analyzing destiny based on the eight-character horoscope, and the specific results need to be comprehensively judged in conjunction with other factors.