A
Chinese era name is the
regnal year, reign period, or regnal title used when traditionally numbering years in an emperor's reign and naming certain Chinese rulers (see the imperial naming conventions). Some emperors have several era names, one after another, where each beginning of a new era resets the numbering of the year back to year one or
yuán (元). The numbering of the year increases on the
first day of the Chinese calendar each year. The era name originated as a
motto or
slogan chosen by an emperor.