Our study of the association between maternal time and developmental outcomes of children and adolescents in the April 2015 issue of Journal of Marriage and Family (Milkie, Nomaguchi, & Denny, 2015a) has drawn much attention, which reflects how strongly researchers and the public care about the relationship between mothers' time and children's well-being. We appreciate the commentaries by Waldfogel (2016) and Kalil and Mayer (2016). Their insights will stimulate research that will further our understanding of maternal and parental time and their relationship to children's and adolescents' well-being.Waldfogel urges investigation of variations in the role of maternal time in influencing child outcomes by social and demographic contexts and suggests examining alternatives to maternal time. We agree and expand on her suggestions in this response. Kalil and Mayer argue that the theoretical framework sets up a straw man. We disagree and briefly articulate how our study derives from aspects of intensive-mothering ideology. Kalil and Mayer emphasize the centrality of mothers' social statuses in shaping children's development and the importance of quality activities for children. These are entirely consistent our conclusions. They are misguided about the interpretation of or quantity of time, however. This is understandable given the complexity of assessing children's time with mothers.In responding to these commentaries, we recap intensive-mothering ideology and the assumptions implied by it. Then we discuss the theoretical and methodological challenges that the commentaries identify, which future research should consider carefully: distinguishing between quantity time and quality of time or activities; conceptualizing children's time mothers compared to alternative time use arrangements; social class and time children; measurement and selection issues; variations by child age, family structure, and child gender; and the role of maternal employment.Intensive Mothering and Its AssumptionsIntensive-mothering ideology places children at the center of mothers' lives and suggests that they require vast amounts of time, effort, and energy from individual mothers (Hallstein, 2006; Hays, 1996). The idea that mothers' time is more valuable for children than is time other caregivers is also an aspect of intensive mothering. Although Kalil and Mayer contend that lower socioeconomic status (SES) mothers do not believe in intensive mothering, studies have shown that they are subject to the same cultural ideal of motherhood as are higher SES mothers (Hays, 1996). Lower SES mothers express the importance of being there and sacrifice as the virtue of good mothering (Damaske, 2011; Edin & Kefalas, 2005; Macdonald, 2009), some of the central elements of intensive-mothering ideology. Regardless of variations in how much people buy into this ideology, it is dominant in the United States (Hays, 1996). Moreover, the debates on maternal employment and the rich history of studying its effects on children deriving from sociological and developmental theories are closely linked to the assumption that the lower quantity of mothers' time allocations to child care is detrimental for children (Bianchi, 2000).Kalil and Mayer repeatedly question our statement on the consequences of intensive mothering ideology for mothers' distress, a topic that motivated the present analysis but was not the focus of it. It is important to distinguish between the ideology of intensive mothering, the actual practice of parenting, and feelings about time children. Intensive-mothering ideology places very high standards on mothers in terms of the appropriate amount of time they should spend their children, which may link to the fact that nearly half of mothers feel as if they are not spending enough time children (Milkie, Mattingly, Nomaguchi, Bianchi, & Robinson, 2004). Importantly, our prior work shows that the feeling of a time deficit children is a strong predictor of poorer maternal well-being (Milkie, Kendig, Nomaguchi, & Denny, 2010; Nomaguchi, Milkie, & Bianchi, 2005). …