Edit in JSFiddle

setInterval(function() { 
    $("#myDiv").hide(); 
    setTimeout(function() {     
       $("#myDiv").show(); 
    },1000);//hide timing
},3000); //show timing

<div id="myDiv">Hi, I'm visible now...</div>

div{
    background-color:red;
    color:white;
    width:10em;
    height:2em;
}