Flexible work schedules are increasingly promoted to improve work-family balance and reduce work-family conflict. However, the impact of these schedules remains debated. Some studies suggest flexible schedules lead to better work-life balance by providing greater temporal control, while others point to a 'flexibility paradox,' where individuals end up working longer hours and having less free time. Existing research suffers from limitations: it often relies on simplified survey questions, ignores the variation in the degree of schedule flexibility, and fails to adequately consider gender and class differences in time use. This study aims to address these limitations by employing rich time-use data from the UK to examine how different types of flexible schedules (limited with core hours vs. unlimited without core hours) affect time allocation among paid work, unpaid work, personal care, and free time, while considering gender and occupational class differences.

The literature presents conflicting views on the impact of flexible work schedules on time use. The Job Demand Control (JDC) model suggests that greater schedule control leads to better work-family balance. However, the temporal regularity thesis and work-family border theory argue that maintaining a clear boundary between work and non-work time is crucial for preventing overwork and role conflicts. Empirical studies have yielded inconsistent results, partly due to the use of simplified measures of flexible work and a lack of attention to gender and class differences. Some studies find that flexible schedules benefit employees' well-being, while others observe the 'flexibility paradox,' where individuals work longer hours and have less free time, particularly women with childcare responsibilities. There's limited research examining the impact of different *degrees* of schedule flexibility, thus requiring further empirical investigation.

This study uses data from the UK Time Use Survey (UKTUS) 2014/2015, a nationally representative survey. The sample includes 1933 employees who provided detailed time diaries for a typical weekday. The dependent variables are time spent on paid work, unpaid work, personal care, and free time, measured in minutes. The key independent variable is the type of flexible schedule used: 'no flexible schedule,' 'limited flexible schedule (with core hours),' and 'unlimited flexible schedule (without core hours).' Occupational class (high, middle, low) and gender are included as moderators. Control variables include age, household income, presence of children under 16, and general health status. Ordinary Least Squares (OLS) regression analyses are used, weighted to account for the complex survey design, to examine the effects of different types of flexible schedules and the potential moderating effects of occupational class and gender.

Descriptive statistics reveal that 69% of respondents had no flexible schedule, 23% had limited flexible schedules, and 8% had unlimited flexible schedules. Multivariate regression analyses show that limited flexible schedules are significantly associated with less time spent on paid work and more free time. However, this effect is conditional on gender and occupational class. Specifically, the positive effects of limited flexible schedules on free time are only observed for men in high occupational classes. Men in lower occupations who use limited flexible schedules tend to work more hours and have less free time. Unlimited flexible schedules do not consistently reduce paid work time or increase free time. The study finds no significant gender moderation effects on the impact of flexible schedules on time use. However, the relationship between limited flexible schedules and time use is significantly moderated by occupational class, particularly for men. For men, limited flexible schedules are associated with less paid work and more free time in higher occupational classes, but the reverse is true in lower occupational classes. These class-based effects are not as pronounced for women. Three-way interaction terms indicated that for free time and paid work, the effects of limited flexible schedules differ significantly depending on the interaction of gender and occupational class.

The findings challenge the simple prediction of the JDC model that more schedule control always leads to better work-life balance. The results support the temporal regularity thesis and work-family border theory, suggesting that limited flexibility may be more beneficial for work-family balance by maintaining clearer boundaries between work and non-work time. The study highlights significant gender and class inequalities in the experience of flexible work schedules. The benefits of limited flexible schedules accrue disproportionately to men in higher occupational classes, while men in lower occupations may experience exploitation. This suggests that flexible work policies may inadvertently exacerbate existing social inequalities if not carefully implemented and monitored. The lack of consistent positive effects for women suggests the persistence of traditional gender roles in time allocation, despite flexible schedule options.

This study offers important insights into the complexities of flexible work schedules and their impacts on time use. It underscores the need to distinguish between different degrees of schedule flexibility and to consider the interacting effects of gender and occupational class. Policymakers should be aware of the potential for flexible work arrangements to exacerbate existing social inequalities and consider targeted interventions to ensure equitable benefits across different socio-demographic groups. Future research could examine the impact of flexible schedules on weekend or holiday time use, explore other dimensions of flexibility, and analyze the interconnected time use patterns within households.

The study focuses on weekdays only, potentially underrepresenting the full impact of flexible schedules on time use. It does not comprehensively assess all dimensions of flexible working arrangements. Data limitations prevent an exploration of cross-over effects of flexible schedules on time use within households. The study also does not explicitly consider the influence of the Covid-19 pandemic on flexible working patterns.