Timeline of the far future
A time capsule is a box or other container that is buried or hidden on purpose and scheduled to be opened many years later.  People place things inside the time capsule so people in the future will find them.  For example, someone might place a game, tool, toy, journal, magazine or book inside a time capsule so people in the future would see how the people who buried the time capsule lived, played and worked and what they liked to read.