Bitcoin needs plenty of time and effort if you are really interested. Spending time in bitcoin is really worth it if you have the eagerness to earn for your living.
Well if you are a long term investors than you can easily on your weekend study about the coin which you need to invest or how market is reacting etc and can make investment based on your research,. You would not require any time in daily busy schedule if you are a full time employee/business man. In case if you want to make some extra money you would require some time to spend.