Speaking of a ‘lack of time’, do we mean the same ‘thing’ as the variable ‘t’ in a graph of some time-dependent development? The following article tries to show that both concepts are extreme examples of the two sides, or faces, of the single phenomenon of time, as common and trivial as it is mysterious. Scientific, numerical time is considered first, followed by the time of the common human experience, the time in the present. It is on the basis of this curious ability to ‘keep in presence’ various events that follow one another, that the scientific concept of linear time has been established and, with it, the possibility to measure the time for scientific and practical purposes.