<!DOCTYPE html><html lang=
"en"
><head>
<meta charset=
"UTF-8"
>
<meta http-equiv=
"X-UA-Compatible"
content=
"IE=edge"
>
<meta name=
"viewport"
content=
"width=device-width, initial-scale=1.0"
>
<title>Document</title></head><body>
<p>
<span
class
=
"hour"
>1</span>
<span
class
=
"minute"
>2</span>
<span
class
=
"second"
>3</span>
</p>
<script>
var
hour = document.querySelector(
'.hour'
);
var
minute = document.querySelector(
'.minute'
);
var
second = document.querySelector(
'.second'
);
var
inputTime = +
new
Date
(
'2021-4-10 23:00:00'
);
countDown();
setInterval(countDown,1000);
function
countDown() {
var
nowTime = +
new
Date
();
var
times = (inputTime - nowTime) / 1000;
var
h = parseInt(times / 60 / 60 % 24);
h = h < 10 ?
'0'
+ h : h;
hour.innerHTML = h;
var
m = parseInt(times / 60 % 60);
m = m < 10 ?
'0'
+ m : m;
minute.innerHTML = m;
var
s =parseInt(times%60);
s = s < 10 ?
'0'
+ s : s;
second.innerHTML = s;
}
</script></body></html>