How to calculate Mercury and Sun constellations?

What are the sun and mercury in the constellation?

The star of tomorrow refers to the constellation that falls on the horizon at the moment you are born. The rising constellation is our external performance, and you are perceived by the outside world. So the way you express yourself can also be known from the rising constellation. The Sun Constellation is a constellation that rises at sunrise on the day you were born. It is what we usually call a constellation. September 20th is Virgo. Sun sign is the most important influence of personality display, followed by rising sign. The moon affects our emotions, their confusion and expression, their formation, inner world and so on. The moon constellation will not affect the expression of external personality, but it will affect the formation of personality. If you want to know something other than the sun sign, it depends on the specific time and place where you were born. You can't know the sun sign until you know your birthday.