During the 15th Five-Year Plan period, the expansion of service consumption is regarded as an important support for high-quality development. Domestic services are a key part of this process. However, longer working hours tighten household time constraints and raise the non-monetary costs of service use. Urban households may therefore fail to increase domestic service consumption in line with income growth. Data from the China Family Panel Studies (CFPS) were used to construct a "time-effect" analytical framework. The effect of working time on domestic service consumption was examined. Firstly, longer working hours significantly reduce domestic service consumption. The result remains robust after income, assets and other factors are controlled. Time allocation therefore constitutes an important constraint independent of income. Secondly, the negative effect is explained from the perspective of service-governance costs. Longer working hours do more than reduce disposable time. They also raise the governance costs involved in purchasing household services. Cognitive burdens and trust costs are increased. Household role norms are also reinforced. The conversion of household service demand into market consumption is consequently impeded. Third, digital literacy and institutional safeguards can partly reduce information asymmetry and perceived risk. However, the structural barriers created by rigid time constraints cannot be fully removed. The results indicate that insufficient service consumption cannot be attributed solely to weak demand. Time constraints have become a more hidden and persistent boundary of consumption. Greater working-time flexibility should be promoted. Household divisions of labour should be reshaped. Service supply should be improved. Institutional safeguards should also be strengthened. It reveals the underlying mechanism by which extended working hours hinder the transformation of household service demand into effective consumption, thereby providing empirical evidence to support the high-quality development of the service sector.