Abstract
We live by using the time for learning and working, a leisure, a rest. Therefore the time is a key concept of our utility. If I make a model of utility constructed by these time, then I consider what this model explain. First of all, I suppose that our utility organizes by a wage and a leisure time. In this time, I suppose that the wage which construct this utility arise by human capital and working time. And also suppose that this human capital arise from leisure time and working time. From this view, we result that both working time and leisure time influence to our utility. That is, I can construct the model by these time. We have a balance of the effect for this utility from both working time and leisure time. Then working time enhances our human capital or our working productivity. This means to equal that leisure time enhances our human capital or our utility.
