After months of bunker-stocking, NASA-calling, and party planning, Dec. 21, 2012 passed with the world still firmly in place. If you believed, however, that the end of the Mayan calendar’s 13th baktun would indeed signify the end of the world, you might not want to breath easy just yet. Matching up modern calendars with Mayan predictions is tricky, German researcher Nikoali Grube told Spiegel Online. He says the 13th baktun may not actually be over until December 24. Nevertheless, Grube emphasizes that whatever the exact date, the end of the baktun — a period of time lasting 144,000 days — represents the end of a era, not the end of the world. The change is comparable to the turn of a millennium. In fact, Grube says, Mayan artifacts include many references to dates that stem far beyond December 2012.