The end of the world will come on Dec. 21, 2012. Or not. While some New Age authors and teachers are touting that date as an apocalypse, a Stetson University professor is challenging the reasoning behind it. At a public lecture at the Volusia County Library Center on City Island today, Robert Sitler plans to discuss "The 2012 Phenomenon: A New Age Appropriation of an Ancient Mayan Calendar," an article he wrote last month for Nova Religio, the Journal of Alternative and Emergent Religions. Sitler, an associate professor of Spanish language and literature, has been studying and teaching Mayan culture since arriving at Stetson in 1994. He contends the Mayan calendar has long been the subject of "gross misinterpretation" on several hundred Web sites and in a continuous stream of books. Those postings and printings are evidence of a growing public interest in the Mayan Long Count calendar, which had fallen out of use by the Mayans of Guatemala, Mexico and Belize, long before the Spanish conquerors had arrived. The 2012 date is the last day of the current "b'aktun" cycle, or period of 144,000 days, and the final day of an even longer period consisting of 13 such cycles. No one knows why the calendar is arranged with an end date, Sitler said. But the Mayans were known for their accurate knowledge of astronomy. "It's a weird concept to many because the calendar seems to have a preordained ending date," said Jeremy Puma, a Seattle resident and St. Augustine native who writes Fantastic Planet, a "gnostic" blog. He noted in an e-mail interview that the Mayans used the calendar for planting crops and other purposes, but the New Age movement "seems to have glommed onto the calendar's more mythological aspects." First and foremost, Sitler and Puma agree, is New Age author Jose Arguelles, most famed for his declaration of a "Harmonic Convergence" in August 1987. The Harmonic Convergence, Arguelles said, was the "exponential acceleration of the wave harmonic of history as it phases into a moment of unprecedented synchronization," and "a shift point into the last 25 years of the galactic beam."