BCE

Common Era (also Current Era, Christian Era), abbreviated as CE, is an alternative naming of the calendar era, Anno Domini (Latin - "in the year of the/our Lord", abbreviated AD). BCE is the abbreviation for Before the Common/Current/Christian Era (an alternative to Before Christ, abbreviated BC).

History
The CE/BCE designation uses the year-numbering system introduced by the 6th-century Christian monk Dionysius Exiguus, who started the Anno Domini designation, intending the beginning of the life of Jesus to be the reference date. Neither notation includes a year zero, and the notations (CE/BCE and AD/BC) are numerically equivalent; thus "2014 CE" corresponds to "AD 2014", and "400 BCE" corresponds to "400 BC". AD,CE and OTT date designations also are numerically equivalent.

Union Time Reform
The Gregorian calendar and the year-numbering system associated with it was the calendar system with the most widespread use in the Union, and was referred to as Old Terran Time (OTT). For millennium, it had been the Union standard. However, because of the Union Time Reform of 5054, the current standard is Union Standard Time (UST) aka New Union Time (NUT).