It?s 2 a.m. and my six-month-old daughter is wide awake. She isn?t crying, and she isn?t hungry?she’s perfectly happy to be hanging out, as long as I don?t leave her alone. But we are on hour two of this wide-awake, ready-to-party mode, and it?s the middle of the night. No matter how much I shush, pat, hum or feed her, her little eyeballs are peeled open. It?s not until we pass the two-hour mark that she begins to yawn and rub her eyes, and I know she?ll finally go back to sleep. 
Like usual, she?d gone down easily at the beginning of the night. It?s become a pattern for us: After our standard evening bedtime routine, I settled into the couch for some kid-free time to relax and re-watch Downton Abbey. But a few hours after I put myself to bed, my daughter inevitably wakes up. She?s happy as can be and ready to play, inspecting the lamb sewn on her sleep sack, even laughing as the cat walks by her crib.  After some Googling, and speaking with sleep consultants, I now know there?s a term for this particular baby sleep phenomenon: split nights. 
What are split nights"
Split nights, segmented sleep, bifurcated sleep?no matter what you call it, it?s frustrating and exhausting to put your baby to bed, only to have them wake in the wee hours of the morning and stay awake for an hour or more. 
Sometimes a baby simply has an off night?we all do! Maybe it?s digestive discomfort or a growth spurt. Perhaps they?re working on a new skill. Underlying issues can cause nigh...