No doubt the best time to play in stock market is the time when there is a heavy volume and this surge of volume is witnessed in first half an hour of the day and last half an hour of the day. Thus make sure that you trade with an expert advice during this period. If you are trading on your own self, than you should avoid trading during these windows and let the dust get settled.
However if you have to ride a trend, than you must jump in the morning itself and if you are an opportunist; than jump in the market as and when opportunity presents itself in the market. One can have a look at best time for trading and make money in the stock market as an informed investor/trader.