This right time to buy and hold the bitcoin for the future growth. It any time to hold the Bitcoin price. So befor buy and sell the bitcoin check the market price every time. Then easy to buy and sell the Bitcoin on time. Bitcoin price is good future coin. So hold and buy wait for the price increase. Bitcoin prices is day by day increasing. Bitcoin is connected the people for the sharing the information.
I think there is no right or wrong time to buy bitcoin. Looking on its historical price graph, I see that everything happens like a stretched spiral. First the price goes down, then it goes back, later it increases. In my opinion, with bitcoin and holding it is always a win situation. All you need to do is to learn how to manage stress when the price goes down and do not rush selling you holdings.
Or you can learn to understand market cycles in order to sell when bitcoin is expensive and buy when everyone is in a panic! It is enough to make several market deals a year to increase the amount of bitcoins in your wallet!