It really depends who you are addressing and what they will understand.
//The Edwardian era or Edwardian period of British history spanned the reign of King Edward VII, 1901 to 1910, and is sometimes extended to the start of the First World War.//
The same debate was had about the start of the millennium which some argued should have started on 1/1/2001 rather than 1/1/2000, but they were clearly in the minority.
It's the old argument about whether the 1st century started in year 0 or Year 1. Was there a year 0 or was year 1 AD preceded by 1 BC?
In which case you need to learn how to count to 100. The first year of the first century was AD 1 and the last year was AD 100. The second century began in AD 101.
The first year of the first century was AD 0 and the last year was AD 99. The second century began in AD 100.
The very first day of AD 0 was, ( using the modern calendar for example only), January 1st 0000. the following year 1st Jan. 0001