私たちはなぜ、今の方法で時間を計るようになったのでしょうか。どの時点で「分」と「秒」が登場したのか。本書は古代ローマから、カエサルによって制定されたユリウス暦の「うるう年」、復活祭（イースター）を固定しようとした1920年代の試みなどを取り上げながら、私たちが行ってきた時間の計測や、時を時間・日・月で変遷するようになった経緯についてひもときます。
   

• An absorbing exploration of an aspect of our lives which we all take for granted
• An accessible look at an immensely complicated subject, using original research and a range of tables and diagrams to fully explain the concepts involved
• There is no comparable introduction to this subject available
• Covers a wide range of cultures

 
Why do we measure time in the way that we do? Why is a week seven days long? At what point did minutes and seconds come into being? Why are some calendars lunar and some solar?
  
The organisation of time into hours, days, months and years seems immutable and universal, but is actually far more artificial than most people realise. The French Revolution resulted in a restructuring of the French calendar, and the Soviet Union experimented with five and then six-day weeks. Leofranc Holford-Strevens explores these questions using a range of fascinating examples from Ancient Rome and Julius Caesar's imposition of the Leap Year, to the 1920s' project for a fixed Easter.