IRS publication page 14 and page 19.
"Death or birth of child. A child who was born or died during the year is treated as having lived with you more than half the year if your home was the child's home more than half the time he or she was alive during the year. The same is true if the child lived with you more than half the year except for any required hospital stay following birth."
Turbotax uses a # of months metric to get at the question of whether the child lived with you more than half the year, so to indicate that a newborn lived with you more than half the number of days since their birth, you have to select "all year" (or any number of months 7 or greater).
