"Dit boek werd twee jaar geleden geschreven."

Translation: This book was written two years ago.

[SD-77]

Could you also say "Dit boek is twee jaar geleden geschreven."?

[Iris_17]

Theoretically there is a difference.

Werd geschreven is in the past simple tense of the passive, which in English is was written.

Is geschreven is present perfect tense of the passive, which in English is has been written.

However, the use of simple past vs. present perfect is not always the same in both languages, so I wouldn't say it's necessarily wrong