BC
From Tardis Wiki, the free Doctor Who reference
BCE is an abbreviation for Before Common Era and is a secular replacement for the Christian dating system of Before Christ and Anno Domini. The year 357 BCE, for example, translates to the Christian dating system 357 BC.
The BCE system is unusual in that the numbers decrease as time passes; the final year in the BCE period is 1 BCE. This is followed by the first year in the Common Era.