我正在创建一个网页，我希望获得这方面的帮助。当 UTCHours 和 UTCMinutes 等于特定值时，我需要弹出一个文本。我想要这样的东西。这就像模型，而不是实际代码。
h = utcTime
m = utcminutes
if (h=x and m=y)
{
function myFunction();
}
【问题讨论】：
setTimeout() 比setInterval() 更合适。如果您计算从现在到它应该运行的时间之间的持续时间，则没有理由每隔一段时间再检查一次。您知道他们需要等待方法执行多长时间。运行间隔会产生不必要的开销。
标签： javascript html date time
setInterval(function(){
now = new Date();
hours = now.getUTCHours();
mins = now.getUTCMinutes();
executeFunctionIfEqualToDefined(hours, mins);
},60000); // this block will run every 60000 milli seconds i.e 60 seconds =1 min
function executeFunctionIfEqualToDefined(hours, mins){
if(hours === x && mins === y){
//execute your code here
}
}
【讨论】：
Low Quality Postsreview queue。造成这种情况的原因（以及可能有人对您的答案投反对票的原因）是您的帖子包含的代码没有解释它是如何工作的和/或它如何解决 OPs 问题。
当然，我不会为你做所有事情，但你去吧。一个开始的基地。
// The button functionality
const $ = (x) => document.getElementById(x);
$('start').addEventListener('click', ()=>{
startTime();
});
$('stop').addEventListener('click', ()=>{
stopTime();
});
// The timer
// set variables
let date,
start,
stop;
function startTime() {
date = new Date(); // get current date.
start = date.getTime(); // get time from current date
// Just output
document.getElementById("showStart").innerHTML = start;
}
function stopTime() {
date = new Date(); // get current date.
stop = date.getTime(); // get time from current date
// just output
document.getElementById("showStop").innerHTML = stop;
document.getElementById("difference").innerHTML = stop-start;
}
我很无聊，所以你去吧。
// The button functionality
const $ = (x) => document.getElementById(x);
$('setAlert').addEventListener('click', ()=>{
setAlert(3); // alert in x seconds.
});
// set variables
let date,
target,
stop,
interval = 1; // integer.
function setAlert(time) {
date = new Date(); // get current date.
target = date.getTime() + ( (time * 1000) - ((interval * 1000) +1000) ); // sets the time it should alert.
/*
* time -1 because it's a 1s interval, that means when it reaches x = y it will alert 1s later by the next "check". This why you need to subtract 1s.
* (time-1)*1000 is because the getTime returns time in ms not in seconds. You would need to make it setAlert(3000),
* i made it bit easier by multiplying the value by 1000 = ms.
*/
// The loop that checks time
setInterval(function(){ // This function makes the "checking each X ms"
if(stop !== target){ // Check if time was reached.
stopTime(); // Check time
}else{
alert("TIME IS OVER"); // When time is reached do this.
}
}, interval*1000); // Refreshes the time each second.
// Just output
document.getElementById("showTarget").innerHTML = target+(interval*1000); // Because the target time has "minus" in it (line 16) it needs to be added to show the real target time.
}
function stopTime() {
date = new Date(); // get current date.
stop = date.getTime(); // get time from current date
// just output
document.getElementById("showStop").innerHTML = stop;
// document.getElementById("difference").innerHTML = stop-target;
}
【讨论】：
delay = new Date().setUTCHours(h, m, 0, 0) - new Date()。 ;-)
function displayAlert(hour,minute){
//create a new Date Object(Current Date and Time)
var date = new Date();
// getUTCHours getUTCMinutes are inbuilt methods
// for getting UTC hour and minute by comparing it with timezone
var utcHour = date.getUTCHours();
var utcMinutes = date.getUTCMinutes();
//display alert when utc hour and minute matches sired time
if(utcHour == hour && utcMinutes == minute){
alert(utcHour + " : " + utcMinutes)
}
}
displayAlert(18,31)【讨论】：