Without artificial light humans wakeup at dawn. When wake-times are enforced by social constraints, such as work or school, artificial light induces a mismatch between sleep timing and circadian rhythmicity (‘social jet-lag’). Reducing evening light consumption ameliorates this social jet-lag.

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Without artificial light humans wakeup at dawn. When wake-times are enforced by social constraints, such as work or school, artificial light induces a mismatch between sleep timing and circadian rhythmicity (‘social jet-lag’). Reducing evening light consumption ameliorates this social jet-lag.