The date is impossible to answer accurately; there is no way of knowing and potentially a lot of ways the Earth could end.
It also depends on whether you mean the Earth as a planet or life on Earth. I think the planet will exist as long as the universe does. There isn’t much that could destroy the entire Planet.
Life on Earth could be wiped out much more easily. My personal view is that a virus of some kind will mutate into a deadly strain with no cure which could quickly spread throughout the world and kill everyone. But some people will be naturally immune and we have really sophisticated medical processes now that could find a vaccine or a cure so this probably won’t kill everyone.
A massive meteor could hit the Earth, although this wouldn’t necessarily wipe all life out immediately, the impact would create a missive ash cloud – many times bigger than the recent volcano ash cloud. A big ash cloud like that could cover the entire globe and block out sunlight, without sunlight plants cannot photosynthesise and food chains would begin to break and eventually everyone on Earth could perish. Many people believe it is an impact like this that killed the dinosaurs.