Transaction without fee If i want to make a transaction and sent it without fee how long it will be getting conf ? 

And my friend told me it will take more than 1 day. Can anyone here explain to me why it can be happen ?
In addition to what Mikko said, there have been some recent stress tests on the bitcoin network in which a flood of low-fee transactions have been pushed through the system. When the blocksize becomes full (currently 1MB per block, though that is configurable [can be smaller, but not larger] by each miner) it is likely that the miners will take the transactions with the highest fees. Since you are talking about a 0 fee transaction, yours would probably be left behind until the more expensive transactions are processed. 

Think of it like a train in which you can pay what you want to ride (and can also pay 0). If there are a bunch of people waving dollar bills around when the train pulls up, the conductor will let them on first. Your cheapness will mean you wait for the next train... unless the same thing happens again (and it might!).

In the recent tests, some transactions took up to 8 hours to get their first confirmation. This may change in the future, assuming the blockchain max size gets adjusted (there is a big debate on what to do next going on right now in the bitcoin circles).