Possible Clues:

• Like students on finals eve
• Studying into the wee hours, say
• Running on Red Bull, say
• Cramming, say
• Likely to sleep in
• Pulling an all-nighter, e.g
• Like someone glued to a screen for hours, maybe
• Watching the ball drop, perhaps
• Doing some binge-watching, maybe
• Awake past the usual bedtime