How we measure the past

Dates are used to help us to identify and remember when things happened in the past or when people lived. History is recorded in dates. We record dates in years and these years make up a sequence of time periods. Sometimes we put dates on timelines to help us to work out when things happened or when people were born. Looking at dates and timelines help us to see how long ago things occurred.

Historians mark time in dates and years and in longer periods of time. For example, a period of ten years is called a decade, and a period of one hundred years is called a century. Were you born in the 21^st century? When were the members of your family born? Were they born in the 20^th century?

You will notice that the 21^st century begins with dates from the year 2000 onwards. The 20^th century means dates from 1900 to 1999. You can identify the name of the century by looking at the dates in the century that came before it. For example, the 15^th century covers the years from 1400 to 1499. If we want to find out about life in the 19^th century, we find out about what happened between the years 1800 and 1899.