Integrated all-day schools (ADS) follow a holistic approach, arguing that different forms of learning (informal, formal, non-formal) are equally important for students, and provide instruction and care by a constant team of teachers and care professionals. Using a qualitative longitudinal design, the research uses development phases to analyze the evolution of the holistic approach to children learning from 2020 to 2022 in three ADS. Findings show that the ADS embark on a school development journey as they try to integrate different learning cultures and professional approaches within one organization. The qualitative data shows a strong start, but challenges emerge in the daily practices. By April 2021, all three ADS teams emphasize the resolution of initial professional conflicts resulting from different professional backgrounds. Staff turnover and changes in management have a strong impact on the development journeys. The conclusion highlights that the non-linear organizational development process requires constant revision of strategy and structure. Commitment of all staff to this integration of care and instruction is crucial, which is impeded by limited time for pedagogical culture development. This article advances the understanding of the development process of integrated ADS and highlights challenges and benefits.