title: how to execute some function on specific time implicitly
body: <p>Can anyone help 
  I need to run a php file or function on a specific time (atmost predifined).
  So i can not find any way to do this , i think about server variable.
  This has to be done without browser i mean there is no chance that browser run at that time it may be or may not. I hope you understand the problem pls give solution Thanks.</p>