The paper proposes a new approach to the relation between socio-economic development and time. Measuring the economic development of a country by GDP it is obvious that the indicator is an insufficient measure in order to illustrate the progress of the society. National Time Accounting is a set of methods for measuring, comparing and analyzing how people spend and experience their time. The approach is based on evaluated time use or the flow of emotional experience during daily activities. In order to determine the level of development an international system of new statistical indicators was elaborated to express development trough the quality of life growing. The indicators are related to the economic level of the country, living and environmental conditions, employment and the quality of human capital in labour market, but also they reflect the household activities, the balance between professional and private life of people, health condition. The U-index helps to overcome some of the limitations of interpersonal comparisons of subjective well-being.