The altima uses a timing chain, not a belt.
A timing chain normally will last as long as the engine. Signs of a failing timing chain are chain noise and or engine that continues to jump time.
Timing Chain
timing chain timing chain
Signs of a worn timing chain are difficulty starting in cold weather with backfire and sudden brief loss of power while accelerating or decelerating ("stumbling").
timing chain timing chain
timing chain timing chain
No Belt=It has a Timing Chain.=
It has a timing chain
Timing chain
It has a timing chain.
Timing chain