Chronians Strength and Intelligence increase by 2. Their Dexterity decreases by 1.

For the sake of carry weight and push/lift limits Chronians count as one size larger. They can also 2-hand versatile weapons with one side of arms and can use each hand independent of the others. If a Chronian wields a 2 handed weapon with one side of arms they have a -2 to attack rolls made with the weapon.

Chronians are proficient in History and can recall pieces of information with extreme clarity. (Anything you, as the player, remember your character remembers.) They can also always tell what time it is and can figure out the age of any object by studying it for 1 minute, through this study they can also learn when something happened to the object, such as when it was damaged or when it was repaired. 

Chronians have Darkvision out to 60 feet. 

Chronians have -2 to all rolls relying on sight when in sunlight. Their time above ground has helped their eyes grow accustomed to light but centuries underground will forever leave their eyes weaker than most.