This is a hypothetical question with insufficient information anyway. The math is easy to do once you've established what the actual drain of the camera is in each operation eg running, zooming, standby etc.

However, I believe your camera (Z7) has a time left indicator like ours (Z1) Our usage tended to be long, continuous with relatively little zooming (which is good for batteries) and we got pretty much what the camera indicated though I never trusted the indicator below an hour. If your camera is in standby for much of the time I imagine you could get eight hours though I doubt it.

Finally,never trust clones, especially in their readout. The info circuits are rubbish and unreliable - we had one once (which was a false economy) which regularly reported 600 hours to run - which it never did. Branded batteries are like good tyres - cheap insurance.