If you hate somebody, it only means that you have lot of meaningless time to spare. If you are busy and live in the present, you cannot think of the past or the future.

There is a well known saying in Vedanta that you cannot hate strangers, you only can hate somebody whom you loved and withdrawal of love is what hatred is.

Love and hate, therefore, are the two sides of the same coin. You cannot have both. You need to make an effort to hate somebody but love is always spontaneous. It is not true that if you love somebody, it means that you have a lot of time to spare. Love comes from the heart and not from the mind or the intellect.