Guilherme Rambo, 9to5Mac:

9to5Mac has learned from sources inside Apple that the company is working on sleep tracking for the Apple Watch, which won’t require any special hardware to work.

And:

While asleep, the Apple Watch will track the user’s quality of sleep using its multiple sensors and inputs, including the person’s movement, heart rate, and noises.

Noises!

One of the issues with wearing an Apple Watch during sleep is that many users choose to charge their Apple Watch at night. Apple thought about this and developed a feature that will remind users to charge their Watch beforehand so they can get through the night.

When wearing the Watch during bedtime, if the user wakes up and starts their day before their alarm goes off, it will automatically turn off the alarm.

This is all fascinating to me. Makes me wonder what I’d do with that information. Will there be an addition to the Health app to help me get better sleep? To take advantage of this information in some way?

Another question: Will this work with an existing Apple Watch model? If so, how far back will it go?

We’ll find out one week from today.