This paper seeks to identify what type of employees are more likely to be satisfied with flexible working time and what type with fixed time, and what drives some other time-related aspects of job autonomy.The paper uses multivariate ordered probit modelling on data from an original repeated survey of Estonian creative R&D employees. The results indicate that high creative intensity of work is a strong predictor of an R&D employee being satisfied with flexible rather than fixed working schedules. Women and employees with less creative and more administrative tasks perceive more constraints on the timing of their work due to jealousy of colleagues and they are more likely to feel that their creativity is adversely affected by their working time arrangements. Employees with flexibility in both the timing and place of doing their work are significantly less likely to perceive working time-related constraints on their creativity or jealousy of their colleagues as a restraint on their working time choices than are those with a fixed working time and place. The higher the salary level of the employee, the more likely they are to feel that the nature of their work constrains their working time choices. The study helps in understanding and alleviating restrictions on time-wise job autonomy that may have considerable adverse effects on how efficiently the intellectual capital of R&D employees is used.