Apple Watch owners can now track Time in Daylight via iOS 17's Health app, a hidden feature using the device's ambient light sensor. Introduced in watchOS 10, this metric automatically logs sunlight exposure without requiring manual input or app setup. Data spans back to June 2023, offering years of insights into daily habits.

The Health app integrates Time in Daylight under Mental Wellbeing, revealing how sunlight impacts physical and mental health. A recent example showed a writer's highest Time in Daylight day came from working outdoors on a MacBook Air, surpassing weekend outdoor activities. This metric shifts focus from exercise-centric tracking to holistic wellness, helping users recognize non-exercise healthy habits.

Apple Health users can access the data via the search bar: type "daylight" to view trends. While optional, the feature’s passive nature makes it a seamless addition to Apple Watch's health ecosystem. No settings are needed to enable it, though users can disable tracking if preferred.

The $299 Apple Watch Series 11 and earlier models support this feature, emphasizing its accessibility. By quantifying sunlight exposure, Apple expands health monitoring beyond traditional fitness metrics, aligning with growing interest in mental wellness. This update underscores the Apple Watch's role as a versatile tool for modern health optimization.