地震はいつ何時起こるか分からない。

English Translation

You never know when an earthquake will happen.

The transcript as well as TTS are incorrect. 「いつ何時」should be pronounced as いつなんどき, not いつなんじ. It’s a set phrase.

  • なんじ for 何時 means “what time” (e.g. 7:35pm).
  • いつなんどき means “anytime in your life” (e.g. during sleeping, taking a shower, while being sick, etc.)