When a story spans decades, it is often not possible for the one actor to play the same character throughout. Heavy make-up might just let the 30 year old play 90, but never under 18. Instead, multiple actors are used for the same role.
A time-shifted actor will usually be credited as playing 'Young Mr. X' or 'Old Ms. Y'.
Time-Shifted Actor has been suggested to play 5 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.