mihir08,
The time to charge o discharge a capacitor depends in how much current you apply to it. But, its most easy. If you use a resistor in series to charge o discharge that formula is:
V -----/\/\/\------||---- GND
t = 1 / (RxC)
It means the time required to the voltage drop from 0 to half of value applied. It's the same for discharge. You can (but is not 100% correct), assume that the time from 0 to 100% of V is twice that value (remember that is not 100% correct, but you can use it as approximate)