Integrator circuit time calculation
The rate of voltage change of a capacitor is proportional to the current.

For example, if it took 2 seconds for the capacitor to go from 0 V to 5 V with xx A applied, then it will take 2 seconds to go from 5 V to 0 V with -xx A applied.  If you keep going, it will take another 2 seconds to reach -5 V.

Go back to the basic equation of what a capacitor does.