Credit: TalTech The Covid-19 pandemic has turned flexible working arrangements a new reality, but differences in employees' preferences and the financial implications for companies still require unravelling. At the time, when the companies are in the quest for competitive advantages in the global economy, cost reductions and productivity gains are becoming increasingly important - well-designed working time arrangements and efficient use of human resources can contribute significantly to both. A key challenge is how to manage to strike the balance between optimal division of the employees' time between work and leisure and the employer's goal of profitability. It appears from Raul Ruubel's doctoral thesis "Working Schedules and Efficient Time-Use in R&D Work" defended at TalTech Department of Economics and Finance that provision of flexible working options may help achieve productivity gains and reductions in personnel costs if it can be assured that the individual characteristics of the employees are taken into account.