Year zero
Year zero does not exist in the anno Domini system usually used to number years in the Gregorian calendar and in its predecessor, the Julian calendar. In this system, the year is followed by . However, there is a year zero in astronomical year numbering (where it coincides with the Julian year ) and in ISO 8601:2004 (where it coincides with the Gregorian year ) as well as in all Buddhist and Hindu calendars.
Timeline of Christianity
The purpose of this timeline is to give a detailed account of Christianity from the beginning of the current era (AD) to the present. Question marks ('?') on dates indicate approximate dates.
The year one is the first year in the "Christian calendar" (there is no year zero), which is the calendar presently used (in unison with the Gregorian calendar) almost everywhere in the world. Traditionally, this was held to be the year Jesus was born; however, most modern scholars argue for an earlier or later date, the most agreed upon being between 6 BC and 4 BC.