In the remote past from the embryo of human civilisation people needed means to measure time and tried various devices making many attempts to create such means. The conditions available then and the low level of social development and its habitual level of knowledge of nature and exact sciences made it almost impossible to create satisfactory methods and devices. Initially, people used several most easily available means such as the Sun, the Moon and seasonal peculiarities as for example the snow in order to measure time in periods – days, months, seasons and years [1].
One of the first devices used to measure the hours in the day was the sundial which measured time relative to the shade cast by a vertically position bar in a flat sunny location. Moreover, the shade moved along an oval-elliptical curve and had a specified length for independent hours depending on the time and season. Later and perhaps parallel to the progress in engineering and trade the sand glass was created [1]. This is a device where a loose material, sand for example, is being poured from a container having a specified volume into another similar container and this is usually completed within a certain period of time. This device samples of which are still kept as antiques was later substituted by the mechanical clocks and devices for measuring time that emerged as a result of the progress in exact sciences like mathematics and physics and initially based on the physical and simple pendulum and its most important for the application scientifically established property: T= 2π√l/g [1].
During oscillation the time T for one pendulous movement at average deviation amplitudes is a constant value, which does not depend on the speed and amplitude of oscillation but only on the length of the arm of the pendulum. This was the solution to the first historically task from system dynamics. An important element from the clock mechanism was thus created and established that was also used for any other device for measuring time or certain parts of time, from 1 sec to 24 hours in a day or more [1]. Gradually developing was the driving technique and mechanism. Weight clocks were also spreading. The driving force in them is the potential energy of a weight mounted at a certain height, which under the action of gravity can turn into kinematical energy and induce mechanical movement into the mechanism driving the time indicating hands on scales and dials of various shapes and constructions. Gradually, other potential energy sources and driving mechanisms were adopted like tensioned spring either spiral or linear [1]. Various electrical current motor driving means were later adopted and recently, such based on solar or atomic power and living nature temperature and energy are being used such as the automatic self-winding clock mechanisms and clocks with solar or heat batteries.
One major problem has always stood in front of design engineers when considering existing time measuring devices and this is the necessity for movement uniformity of the mechanism. The intervals being indicated should have the lowest possible difference from the exact time. From all existing clocks the one that is most satisfactorily meeting this demand is the pendulum with an arm driven by means of an anchor and anchor wheel but due to the substantial dimensions of such a regulator this has almost been substituted by a regulating mechanism, which also uses a pendulum with an anchor mechanism but has the shape of a flywheel with a spiral spring. This is widely used type of regulator and provides high precision of movement and time measurement [1].
Modern society has created and made available a number of various time measuring devices and mechanisms starting with the ordinary clocks indicating the hour, minutes and seconds in the day, the day from the week, the date, year and time differences along the globe meridians and longitudes and end up in the most accurate devices for measuring processes and time with an accuracy of micro- or nano-seconds in nuclear physics and other sciences [2].