我怎样才能用 javascript 做日间计时器？

Question

I need timer with day. I want to change automatically rows at HTML tables every day.

For example; If day 11 or 12 or 25 and month February and hour 08, change rows with "Hello." .

 function time() { var xdate = new Date(); var $second = xdate.getSeconds(); var $minutes = xdate.getMinutes(); var $hours = xdate.getHours(); var $day = xdate.getDay(); var $date = xdate.getDate(); var $month = xdate.getMonth(); var $year = xdate.getFullYear(); console.log($date + "/" + $month + "---" + $hours + ":" + $minutes); setTimeout("time()", 1000); var x = document.getElementById("help1"); if ($date == (11 || 12 || 25) && $month === 1 && $hours == 08) { document.getElementById("help1").innerHTML = "Hello" } } time();

 <span id="help1">Hi</span>

Answer 1

You probably meant

 const pad = num => ("0"+num).slice(-2); function time() { var xdate = new Date(); var hours = xdate.getHours(); var minutes = xdate.getMinutes(); var seconds = xdate.getSeconds(); var date = xdate.getDate(); var month = xdate.getMonth()+1; // months start at 0 var year = xdate.getFullYear(); x.innerHTML = date + "/" + pad(month) + "---" + pad(hours)+":"+pad(minutes)+":"+pad(seconds); // day 11 or 12 or 25 and month February and hour 8 if ((date === 11 || date === 12 || date === 25) && month === 2 && hours === 8) { x.innerHTML = "Hello" // clearInterval(tId); // this will stop the timer } } var x, tId; window.addEventListener("load",function() { x = document.getElementById("help1"); tId = setInterval(time,1000); });

 <span id="help1"></span>