DJs and producers live by a 4 AM body clock, often spinning until sunrise...

https://elizabethsbrilliantnews.almoheet-travel.com/the-real-downside-of-just-one-drink-after-a-set-a-touring-dj-s-sleep-reality-check

DJs and producers live by a 4 AM body clock, often spinning until sunrise before catching 9 AM flights