Circadian Rythm

Blue light affects your body clock when it reaches your eyes, and the effect is different depending on your body clock. Circadian Rhythm tracks that daily pattern into a simple, personal guide on your Garmin watch which tells you when blue light shifts your clock to be earlier and when it shifts it later. For most people shifting earlier is desireable since that means making it easier to fall asleep in the evening and sleeping through the night, but shift workers or travelers might have other goals. WHAT IT SHOWS • Blue Light Effect glance — Shift Later, Shift Earlier, Uncertain, or Low Effect without opening the app • Blue Light Now — the current estimate, when it changes, and what comes next • Light Windows — today's estimated Shift Later and Shift Earlier periods • Estimated Sleep Schedule — the tracked estimated sleep over previous nights • Body Night — an estimated start of internal night with a visible uncertainty range • Optional evening reminder when blue light is more likely to shift your body clock later • Dim warm colors while the shift-later window is active, so checking the guide is not itself a bright blue-light exposure RUNS ENTIRELY ON THE WATCH Circadian Rhythm uses recent overnight patterns available on your watch to keep the guide aligned with your routine. Two recent nights unlock guidance, and wearing the watch to bed keeps it current. The app does not upload its estimates or overnight history. No separate account, companion app, or server is required. GOOD FOR Understanding the timing of evening screens and other blue-light sources, comparing morning and evening exposure windows, and seeing how your recent sleep routine relates to your estimated body night. REQUIRES A compatible Garmin watch with Body Battery, worn overnight for at least two recent nights.