[ruslan_mart]

var timeEventHours = 7;

function setTimeEvent() {
   var date = new Date,
       hours = date.getHours(),
       minutes = date.getMinutes();
   hours = timeEventHours - hours + 24 * (hours > timeEventHours);
   setTimeout(timeEventHandler, 36E5 * hours - 6E4 * minutes);
};

function timeEventHandler() {
   console.log('Hello world!');
   setTimeEvent();
};

setTimeEvent();