To bring a thing back to a state it held before. Restoration returns the form and never the interval.
Old French restorer, from Latin restaurare (to restore, to rebuild), from instaurare (to renew): in- (upon) + a root related to Greek histanai (to make to stand); to restore is to set a thing standing again in a state it held before.
To bring a thing back to a state it held before. Restoration returns the form and never the interval, exactly as the root's standing-up-again says nothing about the time spent down.