Convert dates BC/BCE into Old Era dates (similar to Holocene Calendar aka Human Era).
This extension converts BC/BCE dates into Old Era dates on Wikipedia and other websites. Old Era is 10,000 years before Christ (from 10,000 BC to 1 BC) that are numbered in chronological order.
You can also use any other timeline by picking the starting point for a timeline yourself.
The extension can potentially detect and convert all BC dates, even those that lack “BC” label. If some date is not being detected you can fix that using tools provided by the extension.
It can also detect and convert dates of the Common era, but only those that have “AD” or “CE” label next to them.