Constellations are determined by the date of the solar calendar. 1988 February 18 Lunar calendar date is April 4th, and the constellation of that day is Aries.
Lunar calendar:1Feb. 98818th.
Ganzhi: Chen Wu Mao Yi is ugly.
Gregorian calendar:1Monday April 4, 988, Aries.
Source: Hua.com.