Sometimes referred to as the fourth dimension, time has a highly geographical relevance. For human geography, population sizes can have as much impact on the ‘tempo of places’ as culture or even climate. In physical geography, the concept of time is indispensable for an understanding of how the natural environment has changed and keeps changing.
In the 21st century, time has been described as being a commodity itself, affecting everything from manufacturing and trade, to financial flows and global transport links.
The general geographic distribution of time zones is based on the general concept of dividing the world into zones of equal time following a 24-hour day around the world. In theory, this means that there are 12 time zones of 15° width in which each differs by one hour’s time difference.
The necessity of time zones was closely linked to growing needs of transport and communication links during industrialisation. British railway companies began adopting Greenwich Mean Time (GMT) which helped to coordinate timetables. In 1880, GMT became standard across Britain and time differences of tens of minutes between cities in the country started vanishing. At a global level, time zones became established in the first decades of the 20th century.

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