New research suggests that the people of the third millennium BCE used giant rocks instead of calendars.

A new study explains how the ancient site of Stonehenge may have been used to keep track of the solar year, which is a tropical year and lasts for a year and a half.

The new findings are based on a careful analysis of the number and the positioning of the stones that make up the site, as well as comparisons with other ancient calendar systems that might have influenced the builders of the site.

It has been known for a long time that studies of Stonehenge can be used to track time and seasons.

The sarsen stones that make up the bulk of Stonehenge all came from the same place, according to new research. It's likely that they were put up at the same time and intended to work together.

Timothy Darvill, an archaeologist from Bournemouth University in the UK, looked at the positioning of the different rings that are part of the monument and how they may have related to a calendar.

The new research adds weight to the idea that Stonehenge was a calendar due to the positioning of the stones and their alignment with the solstices.

The proposed calendar works in a very straightforward way, according to Darvill.

The intercalary month is dedicated to the deities of the site and is represented by the five trilithons. Markers are provided by the four Station Stones outside the Sarsen Circle.

Each year, the winter and summer solstices could be seen through the same pair of stones.

This would have been a way of checking the errors. If the Sun were in the wrong place on the summer solstices, the ancient people of Wiltshire would have known that they had messed up.

It is possible that some of the missing or moved stones on the site were responsible for keeping track of these, as none of the arrangements seem to match the 12 months that make up a year. The architecture of Stonehenge has been split into two parts to match the two longest days of the year.

It would not have been the same at the time that Stonehenge was first built. Similar solar calendars have been recorded in Egypt during a time period known as the Old Kingdom, and in other regions as well.

The solar calendar was developed in the eastern Mediterranean in the centuries after 3000 BCE and was adopted in Egypt as the Civil Calendar around 2700 BCE, and was widely used at the start of the Old Kingdom.

It is not clear if this knowledge could have made it all the way to the south of England. The design and construction of Stonehenge is unique and may have been developed by the local population.

Travelers from the Mediterranean region may have brought teachings about the intricacies of solar calendar designs with them from the AmesburyArcher, a historical figure who was born in the Alps but later settled in Britain.

The research suggests that some of these questions might be answered by future artifact analysis and DNA work. The people of the time lived and celebrated in a way that is better understood now that Stonehenge is a fully working calendar.

Finding a solar calendar represented in the architecture of Stonehenge opens up a whole new way of seeing the monument as a place for living.

A place where the timing of ceremonies and festivals was connected to the very fabric of the Universe.

The research has been published.