Children living in a shared-time parenting arrangement following separation (also known as joint physical custody or dual residence) spend equal or near-equal amounts of day and night time with each parent. Little data exist regarding developmental sequelae of such arrangements for infants. The current study examined a theoretically driven question: Are there associations between quantum of overnight stays away from a primary resident parent and the infant’s settledness, or emotion regulation with that parent? Nationally representative parent report data from the Longitudinal Study of Australian Children (LSAC) were used Three age bands were studied and three level of overnight care contrasted. When parenting style, parental conflict and socio-economic factors were controlled for, greater number of shared overnight stays for the 0–1 year old and the 2–3 year old groups predicted some less settled and poorly regulated behaviours, but none for the 4–5 year old group. Limits of these data are discussed, including application to the individual case. Findings suggest emotional regulation within the primary infant-parent relationship is one useful index of infant adjustment to parenting time arrangements.