With all these bizarre twists on English grammatical features in Dutch, it's nice to see something familiar.
I gather this means that a century has ended.
But it doesn't accept, "a century is finished"? I'm confused.
The (male) pronunciation of "eeuw" at slow (turtle) speed sounds distinctly and confusingly as if it ends in a "L" sound. At normal speed the pronunciation is as expected.
Can you also say, een eeuw is voorbij and een eeuw is op/om?
een eeuw is voorbij, yes.
een eeuw is op, no.
een eeuw is om, mmm doesn't sound completely wrong, but I wouldn't
Voorbij is certainly correct. Om should be fine too
...And a new one begins.