As time goes by
Chronological understanding in the national curriculum for history, at both key stages 1 and 2, divides into two key themes. First, the placing of events into chronological order and periods of time. Second, the mechanics and vocabulary of chronology. In developing pupils' understanding of these themes timelines can be a useful teaching aid, not only for teaching the mathematics of dating, but also allowing pupils to visually track the events of a culture or place and compare them with world events happening at the same time.
The aim of early work on chronology should be to build an awareness of the "flow" of time and how humans divide it up. This can begin in KS1 with timelines linked closely to the pupils' own experiences, such as the school day. Create timelines in a context which makes them meaningful to pupils.
These can either be period timelines, such as key events during the life of Florence Nightingale, or themed timelines, such as toys through time.
In KS2 pupils will encounter the use of bc and ad. The basic concept for these sets of dates is mathematical. One is a set of negative numbers (bc) and the other a set of positive numbers (ad). If pupils have studied negative numbers in maths this is a good comparative example to give as they will already understand how it works. If they haven't yet studied this, start with a practical activity.
Hand out sheets individually marked with the years 1ad to 7ad and ask pupils to stand in order from left to right. Explain that events before 1ad happened before the year recorded in the Christian faith as the birth date of Jesus Christ. ad stands for Anno Domini, which is Latin for "the year of the lord". The English words "before Christ" give us bc.
Hold up a sheet marked 1bc and ask the pupils to suggest where it should go in relation to the existing numbers. Once they have placed this number correctly do the same for the years 2bc to 7bc. Remember that unlike maths there is no year zero. Instead the end of 1bc runs straight into the start of 1ad. Another way to tackle this concept is with a set of sticky notes.
Mark notes with a set of bc and ad years and ask pupils to put them in order. They can move the years around as new years are added.
Older KS2 pupils who have a good understanding of the concept of bcad can be introduced to other dating systems. For example, in some books the letters bce are used instead of bc. The abbreviation stands for "before the common era" and is a way of naming the years referred to as bc, but without attaching the time to the name of "Christ". In this case the letters ad are replaced by the letters ce, standing for "common era". This system uses the same numbering method as the bcad system.
Other cultures, however, use different key events as the basis for their dating system. The Torah, the Jewish sacred book, tells when God created the world, and is the basis for the Jewish system for numbering years. In the Jewish system the year 2000ad would be the year 5761.
The Muslim system of numbering years starts with the year in which the prophet Muhammad moved from Makkah (sometimes written as Mecca) to Medinah (or Medina), thus the year 2000ad is the Muslim year 1422ah. The abbreviation ah stands for the Latin Anno Hegirae or the Arabic Al-Hijra, meaning "the years after the emigration".
Katharine Wiltshire is education officer at the British Museum, London and is author of The British Museum Timeline of the Ancient World (see review)