使用Javascript / ajax根据服务器时间和日期加载新数据

I currently have a JS ajax script to load data from the Database, where the query is in load.php How would I make auto load new content separately based on the server time and date? Such as rather than having the whole DB table refresh every "5 Seconds" But loading the current data once, then new data based on server time/date. Here is my script>I currently have a JS ajax script to load data