Abstract
Diurnal rhythms significantly affect the within-person fluctuations of employee outcomes, such as employee motivation, performance, and well-being at the workplace throughout the day. The study examines these day-level fluctuations in employee outcomes through the lens of diurnal rhythms theory using a longitudinal study. Multilevel structural equation modeling (ML-SEM) is used to examine the within-person fluctuations in the causal effects of the research models linking employee motivation, service performance, and well-being throughout the workday. Similarly, cross-sectional modeling is conducted to test causal effects in the research model at each time-point separately. Moreover, Multilevel latent growth curve modeling (MLGCM) and graphical analyses of the composite scores of study constructs are conducted to examine the within-person fluctuations across the workday. Results demonstrate significant within-person fluctuations in the causal effects over the course of the workday. Furthermore, MLGCM and graphical analyses of the composite scores of study constructs across the workday illustrate the day-level fluctuations in accordance with the theory of diurnal rhythms, thereby indicating the effect of diurnal rhythms throughout the workday. The study contributes to the literature of organizational behavior by drawing insights from the diurnal rhythms that help schedule work tasks and optimize employees' service performance and workplace well-being in service-based organizations