Alma 40:4

Behold, there is a time appointed that all shall come forth from the dead.—Now when this time cometh, no one knows; but God knoweth the time which is appointed.

There is a set time when all people will come back from the dead. No one knows when this time will come. But God knows the time.

There’s an appointed time when everyone will come back from the dead. When that time is, no one knows—but God knows when it’s set to happen.