Minecraft 1.18 Release Date and Time
We don't know the exact time it will come out just yet but we can make a guess based on when Caves and Cliffs part one released.
It came out around 10 am PST / 6 pm GMT so we're anticipating a similar release. There's always a chance we could see issues with it going live so give it an extra hour if it needs it.
How to Download Minecraft 1.18
This process should happen automatically as the update goes live, regardless of your platform. This being said, you can always manually install if you need to.
On PC, you can just boot up the game and it should start to install. If this doesn't work for any reason, you could try a fresh install by deleting and downloading the game again. Make sure to back up your saves before doing so.
How to play Minecraft Caves and Cliffs part two early
Although it may not be worth doing with the release just around the corner, you can get the latest release candidate right now.
If you have Minecraft Java, you can access it right now. Make sure to back up all your saves to avoid losing your old worlds in the process.