While human lifespan has dramatically increased over the years, the focus is shifting to healthspan, the duration of ones lifespan in which one is fit and healthy. Longer lifespan has created new challenges for biomedical sciences and there is an urgent need to better understand factors supporting healthy aging. Growing evidence suggests that biological (circadian) clocks are functionally linked to aging, and age-related pathologies including neurodegenerative diseases. Research conducted in this dissertation supports the neuroprotective effects of clocks, and provides a comprehensive picture of aging of the circadian system at behavioral and molecular levels. It also highlights the importance of peripheral clocks in delaying aging and promoting healthspan. Insights obtained from basic research conducted in short-lived fruit flies shall likely illuminate respective molecular mechanisms by which healthy clocks may retard neurodegeneration and aging in humans.