The 1st century BC, also known as the last century BC, started on the first day of 100 BC and ended on the last day of 1 BC. The AD/BC notation does not use a year zero; however, astronomical year numbering does use a zero, as well as a minus sign, so "2 BC" is equal to "year -1". This is the 100th century in the Holocene calendar; it spans the years 9,901 to 10,000.   1st century AD (Anno Domini) follows.