The gender gap in time use and its impact on health and well-being are still prevalent. Women work longer hours than men when considering both paid and unpaid (eg, childcare and chores) work, and this gender disparity is particularly visible among parents. Less is known about factors that could potentially mediate or moderate this relationship (eg, work-family conflict and gender role beliefs). Ecological momentary assessment (EMA) allows for the documentation of changes in momentary internal states, such as time use, stress, or mood. It has shown particular validity to measure shorter-term activities (eg, unpaid work) and is thus useful to address gender differences. The feasibility of the daily EMA surveys in a parent sample will be examined. The associations between time use, well-being, and stress will be examined, along with potential moderating and mediating factors such as gender, gender role beliefs, and work-family conflict. Finally, the act of monitoring one's own time use, well-being, and stress will be examined in relation to, for example, the quality of life. We conducted a quasi-experimental, nonrandomized controlled trial with 3 data collection methods, namely, online questionnaires, EMA surveys, and qualitative interviews. The intervention group (n=64) will participate in the online questionnaires and EMA surveys, and a subsample of the intervention group (n=6-17) will also be invited to participate in qualitative interviews. Over a period of 1 week, participants in the intervention group will answer daily EMA surveys (4 times per day). In contrast, the control group (n=17) will only participate in the online questionnaires at baseline and after 1 week. The following constructs were surveyed: sociodemographic background (eg, age, gender, and household composition; baseline questionnaire); mediators and moderators (eg, gender role beliefs and work-family conflict; baseline and follow-up questionnaires); well-being, quality of life, and trait mindfulness (baseline and follow-up questionnaires); momentary activity and well-being, as well as state mindfulness (EMA); and feasibility (baseline and follow-up questionnaires as well as interviews). We anticipate that participants will regard the daily EMA as feasible. Particular daily time-use patterns (eg, high paid and unpaid workload) are expected to be related to lower well-being, higher stress, and health-related quality of life. These associations are expected to be moderated and mediated by factors such as gender, gender role beliefs, work-family conflict, and social support. Participants in the intervention group are expected to show higher values of mindfulness, well-being, health-related quality of life, and lower stress. Patient recruitment started in November 2023 and ended in mid April 2024. Data analysis commenced in mid April 2024. This study aims to provide valuable insights into the feasibility of using EMAs and the potential benefits of activity tracking in various aspects of daily life. Open Science Framework 8qj3d; https://osf.io/8qj3d. PRR1-10.2196/54728.