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Spheroids are generally dominated by stars older than 1 Gyr. In such populations, changes with age are less dramatic than they are for younger systems. The best age diagnostics come from photometry reaching low-mass (~ 0.8 Modot) main sequence (MS) stars; such photometry enables the reconstruction of the complete star formation history with an age resolution of ~ 1 Gyr, but it is difficult to obtain such photometry outside the Milky Way system, due to crowding and depth limitations. Age constraints are also available through photometry of later evolutionary phases, such as the horizontal branch (HB), asymptotic giant branch (AGB), and red giant branch (RGB); relative to MS stars, these brighter stars can be detected in more distant and crowded regions, but the age resolution is poorer, allowing one to distinguish between young (< 3 Gyr), intermediate-age (3-8 Gyr), and old (> 8-13 Gyr) stars.