Your newborn is likely to have his or her days and nights mixed up for anywhere
between 1 to 12 weeks. This is because during pregnancy your daytime activities
rocked your baby to sleep and at night when you were relaxing your baby was more
active. Also, it’s not until about 12-15 weeks that babies start producing
enough of their sleep/awake hormones so they can have the timings mixed up. But
with age, it gets better and the child gets used to following a day and night
ritual.