Time helps us keep track of changes by marking moments with dates, showing how long events last, and telling us the order in which things happen. To measure time accurately, we use a method called chronometry or, in simpler terms, timekeeping. Another related idea is horology, which usually refers to mechanical devices like clocks. Time can be measured by pinpointing the exact moment something happens or by looking at how long it lasts.
There are two main ways we measure time in our everyday lives, depending on how precise we need to be. Clocks, which are physical devices, help us keep track of time more accurately, especially for periods of less than a day. On the other hand, calendars are more like math tools that help us calculate longer periods, more than just a day.
When we want to study the past and figure out the order in which events occurred, we use chronology. This helps us organize events in their time sequence. We can group events into different periods, which is called periodization. All these things together—chronology, periodization, and understanding the past—are part of the study of history.
Measuring time involves using different units, depending on how short or long the period is. Physics uses tiny units, while our everyday lives use units like seconds, minutes, hours, days, months, and years. Geological and cosmological time scales deal with much larger units.
Throughout history, people have had different ways of measuring time. But now, with the whole world connected and working together in science, we’ve adopted universal and super-accurate standards for measuring time.