How to make ios5 launch my app at some time?

You can't. You're not in control of when you app executes in iOS. Your app can only launch because the user has launched.

 

The closest you can come to this is to set a local alert which will pop up a message asking the user to launch the app at a certain time.

Which is actually probably exactly what your user would want... why would they want it to launch against their will?

 

They are thinking lolschmandroid. (or Android)