Answer:
December 21
Step-by-step explanation:
December 21st are days that has brightest areas on the celestial sphere in which a group of stars forms an imaginary outline or pattern in the sky at sunset, and they are visible all night long during the winter months.)
Due to the rotation of the earth, the stars would seem like they're moving. As the Earth rotates from west to east, the stars appear to rise in the East, moving across south to set in the west.