Venus is the second planet away from our sun in our solar system. It has often been called "Earth's twin" because it is roughly the same size and composed of about the same material as Earth. Venus never ventures too far from the sun, as viewed from Earth, and is the second brightest object in our night sky, after the moon. Venus achieves its brightest appearance shortly after sunset and just before sunrise, which is also why it is called the "Morning Star" and the "Evening Star". The best time to catch this brightest appearance would be just as the sun is setting, or just before the sun comes up. Venus has a retrograde rotation compared to the Earth, which means it from right to left, when viewed from its north pole.
Thanks for the answer to first part. What is the duration (days) it is seen as Morning Star and what is the duration (days) it is visible as eneing star?
It appears in the morning and in evening for 1 hour.