Is 2021 BC or AD?

The Dionysian era distinguishes eras using the notations BC (“Before Christ”) and AD (Latin: Anno Domini, in [the] year of [the] Lord). The two notation systems are numerically equivalent: “2021 CE” and “AD 2021” each describe the current year; “400 BCE” and “400 BC” are each the same year. Dec 6, 2021

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