Purpose -This paper aims to explore the management of working time flexibility and firm performance, measured by operating hours, in small and medium-sized enterprises (SMEs) in Europe. Design/methodology/approach -The paper analyses the European Capital Operating time, Work and Employment Survey (EUCOWE), designed to collect workplace information on operating hours. With data on more than 17,000 establishments in six European countries -France, Germany, The Netherlands, Portugal, Spain and the UK -the paper analyses working time patterns and operating hours.Findings -The authors show the positive relationship between company size and operating times and how SMEs make more limited use of more advanced forms of working-time organisation that may allow them to extend their operating hours. The use of less complex working time measures such as overtime does not have the same positive association with operating hours. However, the results also highlight that smaller establishments can still benefit from the adoption of certain working time practices. The results suggest that the influence of the regulatory environment on the use of working practices or the duration of operating hours is not straightforward, and as such the impact of national regulatory frameworks cannot be discounted in the country-specific differences identified. Originality/value -The paper uses the first comparable data on operating hours and working patterns to demonstrate the limitations on SME operating times across European countries.