The recommended time is AT LEAST two minutes.

I know it might feel like an eternity when you’ve had a long day and all you want to do is climb into bed. But to clean your teeth effectively it should take 120 seconds twice a day. Two minutes allows people to clean all surfaces of all teeth effectively. 

Divide your mouth into quadrants (means four parts) and brush each quadrant for 30 seconds. 

Some toothbrushes, like Sonicare, have a built in timer to make it easy. This is an imported power brush by phillips but you can try out the cheaper indian options like COLGATE 360 POWER BRUSH or ORAL B

common powerbrushes