HealthKit Time in Daylight: sample granularity, latency, and relationship to Health app values

Hi,

We are integrating HKQuantityTypeIdentifierTimeInDaylight into a research application and have a few questions about how developers should interpret the data returned by HealthKit.

Specifically:

1. Should TimeInDaylight samples be treated as having a fixed minimum temporal granularity (for example, approximately 5-minute intervals), or is the sample duration implementation-dependent and subject to change?
2. Is there any expected latency between a daylight exposure event and the corresponding TimeInDaylight sample becoming available through HealthKit? For example, are samples intended to appear shortly after exposure, or only after periodic processing and synchronization?
3. In the Health app, each Time in Daylight sample displays a Maximum Light Intensity (lux). Is this value available through the public HealthKit API (e.g., metadata), or is it only used internally by the Health app?

More generally, should developers consider TimeInDaylight to be a high-level derived metric rather than expecting a direct correspondence with underlying ambient light sensor observations?

Thank you.