Can you leave the group for one day and then go back to the group to continue to the end?

You can't leave the group, because the tour guide should ensure the safety of every visitor.

If you really want to leave the tour group, you have to look at the contract signed by the tour group to make sure it doesn't say that you can't leave the group. Then, if you are sure to leave the tour group for one day, you should communicate with the tour guide in advance, and you will be asked to sign a disclaimer if you agree.