The length of the year is determined by the Sun, particularly, by the time the Sun goes full cycle through the Zodiac signs - 365 days, approximately 30 days in every sign. One sign takes 30°of the Sun's path. Every day the Sun makes precise step on 1°. From the Earth, the Sun or the Moon are never retrograde. It means that they never go back in motion, they are moving strictly forward and start they cycle over and over again.
From the Earth to the Sun: 150,000,000 km. Mass: 334 000 times larger than our planet.
The Sun's element is fire. The essence of the Sun is tempered and dry. The Sun governs Leo and reaches its peak being in Aries. The Sun is associated with heart. It is a symbol of the leader and ruler of the family, society, country etc. The Sun reveals its characteristic during the phase from 20 years to 40 years.
The Sun representatives are rather choleric.
By the character: Sun people are extraverted, helpful and energetic, as well as hot-tempered.
The Sun hides in the ego of each person, in ambitions, ability to be honest with yourself and listen to what you really want and implement it. The Sun is ego-centered, while the Ascendant is rather outer-centered.
The Sun was always a symbol of masculine energy, and favors men or generally manly manifestations in any person. The Sun represents leadership, the company's chief, family's leader, active and influential citizen etc. Regardless a gender, the Sun is associated with controlling, powerful, and decisive energy. A lot of people want to become someone influenced by the Sun, because such qualities are often associated with success and power.
The Sun is the center and a backbone for a family, providing light and confidence. That's why in family life the Sun brings bravery, sincerity, love, and desire to share. However, it is often paired with egotism, snobbism and oral aggressiveness.
Often, in a chart of a woman, the Sun (being a masculine energy) implies a certain man in her life like father, brother or partner in some cases.
As for the period of life from 20 to 40 years - the Sun is associated with younger years, when the person mostly grows and develops, nurturing hopes, ideas and plans for future.