have no exactly time when to trade, you have to follow news, events daily and study technical tools RSI, Bollinger bands...to sell and buy to get profit, and one more impotant note you need to know NOW market are uptrend, downtrend or sideway to target profit ( 1%, 5% ...)
You need to follow the basic market rules which will help you in making profit in trading. Trading with the Bitcoin will result in huge profit for long term while with the less valuable coins like Altcoin and Litecoin will result in small profits which will make huge profit after many attempts. Now buy the Bitcoin in this low market and wait for the time to come so that you may sell it on high price for profit.