Millions of people celebrated the beginning of the 21st 'century' on January 1, 2000.
We were discussing how Americans lived at 'the turn of the' 19th/last 'century'.
When the prince got married, it was called the wedding of the 'century'.
(..) Here we go! Lost diadem of Ravenclaw? Hasn't anyone heard of this? It's quite famous. Yes. But, Luna, it's lost. For centuries. There's no person alive today who's seen it. Excuse me, can someone tell me what bloody diadem is? It's a sort of crown. You know, like a tiara. (..)2011 Harry Potter and the Deathly Hallows: Part 2