In astrology, an Astrological Progression is a timing technique that advances natal-chart positions according to a symbolic measure of time in order to examine longer-term development and changing areas of emphasis. Several progression methods exist. One of the most widely used is secondary progression, which commonly treats one day after birth as symbolically corresponding to one year of life. Astrologers may examine progressed planets, angles, signs, houses, and aspects in relation to the natal chart when exploring evolving themes, transitions, and periods of personal development. Progressions are interpretive timing tools and do not establish that particular events or outcomes are predetermined.