Complex sentence: On June 7,2017 at 6PM KST, the music video for "Happy" was released on YouTube and Naver V LIVE and "Happy Moment" was made available for download on Melon in South Korea and iTunes worldwide.
Split into simpler sentences: On June 7,2017, the music video for "Happy" was released on YouTube and Naver V LIVE. The album was made available on the 7th at 6PM KST on Melon in South Korea and iTunes worldwide.