In astrology, a Secondary Progression is a timing technique based on the symbolic principle that one day after birth corresponds with one year of life. Astrologers calculate the positions of the Sun, Moon, planets, and sometimes chart angles for the appropriate number of days after birth and interpret those progressed positions in relation to the natal chart. Particular attention may be given to progressed sign changes, aspects, lunar phases, and contacts with natal planets or angles. Secondary progressions are commonly used to explore gradual development, changing areas of emphasis, and longer-term internal processes. They are interpretive tools and do not establish that specific events or outcomes will occur.