Day/night confusion
Your newborn doesn't know that 2 PM and 2 AM are supposed to feel different. For the first 2 to 3 weeks, this is normal. Help them sort it out: keep days bright and social (open blinds, talk normally, go outside), and keep nights dark and boring (dim lights, whisper, minimal stimulation during feeds and changes). Most babies figure it out by 3 to 4 weeks.

