The acronym "C.E." stands for "Common Era" and is used as an alternative to A.D. (Anno Domini) in the Gregorian calendar to designate the years after the birth of Jesus Christ. While "C.E." is the most widely accepted synonym for A.D., other options do exist. For example, "Christian Era" and "Current Era" are also commonly used to refer to the same period. Some scholars use "Vulgar Era" to avoid any religious connotations associated with "Christian" or "Common." Additionally, "BCE" (Before the Common Era) can be used to denote the years before the current era, instead of the traditional "B.C." (Before Christ).