Emma Stone was an easy baby -- for about 22 hours a day. "But late every afternoon, it was like she was possessed by demons -- I couldn't get her to stop crying," says her mom, Suzanne, of Exeter, New Hampshire. "Sometimes it was so bad that my husband would come home from work to find both Emma and me wailing our heads off."
No recent scientific study out there proves that babies are especially fussy between 4 and 6 p.m. But parents and pediatricians use vivid language to describe this period, such as "the witching hours," "the arsenic hours," or in Emma's case, "sundowners" -- because Emma got agitated promptly at sunset. "I hear about it constantly," says Parents adviser Jodi Mindell, Ph.D., associate director of the sleep disorders clinic at the Children's Hospital, in Philadelphia. "It's a difficult stretch of time for almost every family."
Why are these hours so hard on infants -- especially during their first three months? "Just like everyone else, babies get frazzled by the end of the day," explains pediatrician Harvey Karp, M.D., creator of the DVD and book, The Happiest Baby on the Block. In addition, it's the time of day when your child is least able to relax. Research shows that a baby's body temperature usually peaks in the late afternoon, leading to maximum wakefulness. So your little one is exhausted -- yet unable to unwind.
Your baby's immature nervous system doesn't help matters, either. "In the first three months of life, her brain is unable to modulate her behavior -- such as making a quick transition from feeling fussy to a calmer state of mind," says Norbert Herschkowitz, M.D., coauthor of A Good Start in Life: Understanding Your Child's Brain and Behavior. Lastly, your newborn's body produces very little melatonin -- the chemical substance that helps establish our sleep-wake cycle. This means she can't readily differentiate between daytime and night, or sleep for more than a few hours at a stretch. By the end of the day, your baby is likely to be worn-out.
Around the time your baby reaches 4 months, his tendency toward sunset meltdowns greatly diminishes. His body starts to produce more melatonin, and his brain matures to the point that he can easily shift his attention from one thing to another. "This means babies are better at keeping themselves busy and pulling out of rough spells faster," Dr. Herschkowitz explains.
But while the period between 4 and 6 months is usually marked by relative calm, don't relax just yet: Your baby will confront new developmental challenges at 6 or 7 months that can cause him afternoon angst once again. "At this stage, babies are highly curious," Dr. Karp says. "They are so excited by all the new things they can do that they often resist sleep and get overtired and cranky."
Even if your baby sails through this period, the 10-month mark—when he's learning to get around by crawling or teetering on two legs -- can be a difficult time. Why? Because mobile babies are tired babies. "Going from here to there from dawn to dusk is exhausting," Dr. Karp explains. This adds to their irritability in the late afternoons, when their bodies are ready to conk out but their zest for exploring is still in overdrive.
These techniques can help your baby be less anxious -- and less likely to shed tears -- at the end of the day.