Carbon-dating of an ancient beam from a Guatemalan temple may help end a century-long debate about the Mayan calendar, anthropologists said on Thursday.

Experts have long wrangled over how the Mayan calendar — which leapt to global prominence last year when the superstitious said it predicted the end of the world — correlates to the European calendar.

Texts and carvings from this now-extinct culture describe rulers and great events and attribute the dates according to a complex system denoted by dots and bars, known as the Long Count.

The Long Count consists of five time units: Bak’tun (144,000 days); K’atun (7,200 days), Tun (360 days), Winal (20 days) and K’in (one day).

The time is counted from a mythical starting point.

But the date of this starting point is unknown. Spanish colonisers did their utmost to wipe out traces of the Mayan civilisation, destroying evidence that could have provided a clue.

An example of the confusion this has caused is the date of a decisive battle that shaped the course of Mayan civilisation.

It occurred at nine Bak’tuns, 13 K’atuns, three Tuns, seven Winals and 18 K’ins — or 1,390,838 days from the start of the count. Attempts to transcribe this into the European calendar have given estimates that vary by hundreds of years.