The maximum displacement of the object is A=0.5 m and its maximum acceleration is a(max)= 3 m/s^2.

An object attached to a horizontal spring is oscillating back and forth along a frictionless table. The maximum displacement of the object is A=0.5 m and its maximum acceleration is a(max)= 3 m/s^2.
How much time elapses between an instant when the object’s displacement is at a maximum and the next time when its speed is at a maximum? 
The answer is 0.64 seconds, please include steps.