Day trading means buying and selling of securities, commodities within a trading hours which includes all online trading positions to be start within an opening and closing hours whether in commodity or security exchange.
In other words day trading also means that practice of the speculation in different securities & commodities of buying and selling different financial instruments but within the same day and such all positions are closed before the market closing day. The traders, jobbers, or day-traders who do day trading are known as Active traders or Day traders.
There are different Exchanges that offers online trading facilities and also has different opening & closing timings in case of commodity market but same in Stock market as stock market is an international market which includes the trading of allover the world.In case of NSE, National Stock Exchange, it remains open at pre- Market timings at 9:00 am but allows the trading to be start at 9:15 am and closed at 3:30 pm, same in case of BSE, Bombay Stock Exchange but McxNcdex has different timings to be opened & closed with different segments as in case of Agriculture i.e. pulses, oil seeds, mentha oil etc, it remains open at 10am & close at 5 pm. While in case of metals, energy, precious metal it opens at 10 am and remains closed at 11:55 pm same day but now it has been declared that after 20th March every year it would remain closed at 11:30 pm everyday except Saturday. At last the McxSx , Multi Commodity Stock Exchange timings are from 9 am to 5 pm but there has been some inauguration for 2013 new research that an stock market would indulge in it and after 11th feb it would open at the same timing in case of commodity but closed at 3:30 pm same day.
As above mostly explanation has been given regarding Day trading now thee is an advantages of the day trading.