Apple today seeded the second beta of an upcoming macOS Sierra 10.12.4 update to public beta testers for testing purposes, two weeks after seeding the first public beta and one day after releasing the second 10.12.4 beta to developers.
Beta testers who have signed up for Apple’s beta testing program will receive the second 10.12.4 macOS Sierra beta through the Software Update mechanism in the Mac App Store.
Those who want to be a part of Apple’s beta testing program can sign up to participate through the beta testing website, which gives users access to both iOS and macOS Sierra betas. Betas should not be installed on a primary machine due to the potential for instability.
macOS Sierra 10.12.4 brings iOS’s popular Night Shift mode to the Mac, allowing users to cut down on blue light exposure in the evening. Believed to affect sleep by upsetting the body’s circadian rhythm, blue light is thought to be more harmful than yellow light.