What constellation am I?

Constellations originated in ancient Greece and naturally adopted the solar calendar.

1May 6, 988 is June 19 of Gregorian calendar (the second day of Dragon Boat Festival in that year), and the sun constellation belongs to jiminy. People in this constellation have dual personalities, can talk and like to make jokes.

Gemini, of course. I'm sure that 1988/6/ 19 is also in line with what you said about the Dragon Boat Festival. People who say Taurus didn't see clearly what you said about the lunar calendar.