O'clock can be also said 點鐘 / 点钟.

Yi dian ZHONG

What Eric said. 现在一点钟 should be correct, as well, I thought.

Is there a nuance I'm missing here? Thanks!

This particular sentence translates really well into German as we sometimes say "Es ist Punkt eins." (literally 'it's point one. ' ) to emphasize on the full hour, as 点 also means "point".

Should be "yi dian ZHONG" (or even "yi dian LE")

"Now-at + one + o'clock"?

In another exercise I'm asked to add 是, why not here?