I'll get right into this idea: It's an outdoor stage that's normal during the day, but if someone goes onstage during the nighttime, they completely lose the ability to recognize "daytime." They perceive the sky as always dark; if someone points out the sun they will say "that's the moon"; and they become distressed at the apparently endless nighttime.
I was even considering that they are anomalously affected by their altered perceptions; i.e. they begin to show vitamin D deficiency that you would get from lack of exposure to sunlight.
What do you guys think? Thanks!