0336 Workday Rhythms and Bedtime Behaviors: The Role of Work Timing and Duration in Bedtime Procrastination

Abstract Introduction Bedtime procrastination, or bedtime delays in the absence of external obligations, is a common behavior that undermines multiple dimensions of sleep health. Most research investigating the factors which underly bedtime procrastination centers on cognitive processes (i.e., self-regulation, rumination, worry). However, individuals may also intentionally delay their bedtime to provide themselves with personal time to wind down at the end of a late work day. The current study sought to evaluate whether work timing, duration, and time spent winding down at the end of the day were associated with bedtime procrastination in a daily diary investigation of young adults’ sleep behaviors. Methods 117 young adult participants (Mage = 25.2, SD = 8.3) completed 14-days of experience sampling assessment, including self-report measures of daily work schedules and morning ratings of prior-night bedtime procrastination and wind down time. Participants also completed the morningness-eveningness questionnaire as a measure of chronotype. Multilevel models were constructed to identify the contributions of work timing (start and end time), work duration, and end-of-day wind down duration in daily bedtime procrastination. Results Across days, average later work start time (B = 0.50, p = 0.017) and end time (B = 0.39, p = 0.043) were associated with higher average bedtime procrastination. However, there were no significant associations observed at the level of daily observations. Work duration and self-reported wind down duration at night were not associated with either average or daily bedtime procrastination. Secondary analyses revealed that, when chronotype was included in the model, the association between work timing and bedtime procrastination was reduced to non-significance. Conclusion Individuals who had later average work timing were more likely to habitually procrastinate their bedtime. However, the within-person association was not significant; daily changes in work schedule were not associated with same-day variation in bedtime procrastination, indicating that this may not be a mechanism for sleep delay behavior. Further, findings suggest that shared variance with evening chronotype may partially explain the observed association between work timing and bedtime procrastination. Future research should distinguish between preferences for doing activities in the evening and circadian timing in the development of bedtime procrastination. Support (if any)