Silver time at Php Js

[briley]

Hello! The problem was: long-term use lags time (in the first minute it is visible). Tell me how to fix it.

<?php 

$timefin = '08:43:40'; date_default_timezone_set('Europe/Moscow'); ? ation

var hours = <? php echo date("H"); ?> ;
var min = <? php echo date("i"); ?> ;
var sec = <? php echo date("s"); ?> ;
var finaltime = "<?php echo $timefin ?>";
function display() {

sec += 1;

if (sec >= 60) {

min += 1;

sec = 0;

}

if (min >= 60) {

hours += 1;

min = 0;

}

if (hours >= 24)

hours = 0;
if (sec < 10)

sec2display = "0" + sec;

else

sec2display = sec;
if (min < 10)

min2display = "0" + min;

else

min2display = min;
if (hours < 10)

hour2display = "0" + hours;

else

hour2display = hours;
time = hour2display + ":" + min2display + ":" + sec2display;
if (time == finaltime) {

$(document).ready(function() {
  $.ajax({
    type: 'POST',
    url: 'response.php?',
    data: 'name=Andrew',
    success: function(data) {
      $('#show').html(data);
    }
  });
});

}

document.getElementById("seconds").innerHTML = hour2display + ":" + min2display + ":" + sec2display;

setTimeout("display();", 1000);

}

display();

<b id="seconds">0</b>

<div id="show"></div>

[rielyn]

Timers in JS are not exact. setTimeout(..., 1000) Not ideally equal to a second.

It's a good option to give a time indicator function many times a second. Inside count the difference between the current time and the intended.

//var finaltime = "<?php echo $timefin ?>"; // timestamp
var finaltime = Math.floor((new Date(2016,5,30,12,0,0)).getTime()/1000);
var timerId = window.setInterval( display, 100);
var el = document.getElementById("seconds");
function display() {

var seconds = Math.floor((finaltime - (new Date()).getTime()/1000))

,minutes

,hours

,days

;
if (seconds <= 0) {

window.clearInterval( timerId);

$.ajax({

type: 'POST',

url: 'response.php?',

data: 'name=Andrew',

success: function(data) {

$('#show').html(data);

}

});

return;

}
days = Math.floor(seconds/86400);

seconds = seconds % 86400;

hours = zeropad( Math.floor( seconds / 3600));

seconds = seconds % 3600;

minutes = zeropad( Math.floor( seconds / 60));

seconds = zeropad( seconds % 60);

el.innerHTML = days + ' д., ' + hours + ":" + minutes + ":" + seconds;

}
function zeropad(n) {

return n < 10 ? '0'+n : n.toString();

}

<b id="seconds">0</b>

<div id="show"></div>