In science and mathematics, time is expressed as a numeric function, or as one of several quantities located on a pictorial graph.

Numbers are of different kind, and they include in order of abstraction: natural numbers, integers, fractions, and real numbers.

Real numbers are represented in terms of a plus or minus infinite decimal expansion.

The rules of arithmetic are precisely the same for real numbers as for fractions, except that real numbers are used to describe infinite concepts, such as the continuity of space and time.

Calculus, which is a comparatively new branch of mathematics, is a system used to describe various rates of change, specifically the rate at which incremental distances change with time. Calculus is used to solve differential equations that model various oscillating motions, fluid mechanics, and electrodynamics.

In physics, events are often expressed in terms of the four coordinates of space and time: X, Y, Z, and T. There are many examples of abstract models of space and time which correspond to real-time events.

In various branches of science, the duration of events are represented graphically in different ways, depending on the kind of events and the conditions under which they occur. For example, the speed and distance of seismic activity within the earth’s interior, and at the surface, is measured by means of seismographic analysis, where a distance of 1 inch on the graph represents 12 minutes in time.