Samidha Visai, center, and Anushree Vora, second from left, dance on a cruise ship while attending an early-morning dance party called Daybreaker in San Francisco, California in August 2015. The two university students from Michigan were spending the summer in San Francisco to intern at health technology start-ups. Daybreaker events, which are substance free dance parties held early in the morning on weekdays, are very popular with young technology workers. Attendees often go straight to work from the event, energized by the dancing for the day ahead.