I have created a date in javascript so:
    var thisDate = new Date(); 
    thisDate.setHours(0); 
    thisDate.setMinutes(0); 
    thisDate.setSeconds(0); 
    thisDate.setMilliseconds(0);
According to Chrome debugger tooltip when I hover the mouse over the variable:
  Fri Mar 15 2013 00:00:00 GMT-0400 (Easte...
  > __proto__: Invalid Date
