Develop Reference

javascript timer to show how much passed since certain time

(function() {
var start = new Date;
start.setHours(24, 0, 0);
function pad(num) {
return ("0" + parseInt(num)).substr(-2);
}
function tick() {
var now = new Date;
if (now > start) {
start.setDate(start.getDate() + 1);
}
var remain = ((start - now) / 1000);
var hh = pad((remain / 60 / 60) % 60);
var mm = pad((remain / 60) % 60);
var ss = pad(remain % 60);
document.getElementById('last').innerHTML =
hh + ":" + mm + ":" + ss;
setTimeout(tick, 1000);
}
document.addEventListener('DOMContentLoaded', tick);
})();
I have a code which counts how much time left till certain time. But I need to reverse it and make it show how much time has passed since certain time.

Since we are talking about the future therefore now > start.
Also if now's hh is less than start's hh we should decrement the start's hh.
So the code would be as follows:
(function() {
var start = new Date;
start.setHours(24, 0, 0); // 11pm
function pad(num) {
return ("0" + parseInt(num)).substr(-2);
}
function tick() {
var now = new Date;
if (now < start) {
start.setDate(start.getDate() - 1);
}
var remain = ((now - start) / 1000);
var hh = pad((remain / 60 / 60) % 60);
var mm = pad((remain / 60) % 60);
var ss = pad(remain % 60);
var diff = hh + ":" + mm + ":" + ss;
console.clear();
console.log(diff);
setTimeout(tick, 1000);
}
tick()
})();

Add milliseconds to JavaScript

I created a simple game for which I need a countdown. Now everything is fine, but I need to add a millisecond to the timer. I used the code found on the internet, but it lacks just those milliseconds. My attempts have not been successful, so I am asking you for help.
var seconds;
var temp;
function countdown() {
time = document.getElementById('countdown').innerHTML;
timeArray = time.split(':')
seconds = timeToSeconds(timeArray);
if (seconds == '') {
temp = document.getElementById('countdown');
temp.innerHTML = '00:00:00';
return;
}
seconds--;
temp = document.getElementById('countdown');
temp.innerHTML = secondsToTime(seconds);
timeoutMyOswego = setTimeout(countdown, 1000);
}
function timeToSeconds(timeArray) {
var minutes = (timeArray[0] * 1);
var seconds = (minutes * 60) + (timeArray[1] * 1);
return seconds;
}
function secondsToTime(secs) {
var divisor_for_minutes = secs % (60 * 60);
var minutes = Math.floor(divisor_for_minutes / 60);
minutes = minutes < 10 ? '0' + minutes : minutes;
var divisor_for_seconds = divisor_for_minutes % 60;
var seconds = Math.ceil(divisor_for_seconds);
seconds = seconds < 10 ? '0' + seconds : seconds;
return minutes + ':' + seconds;
}
countdown();

Converting decimal to hours and minutes - Javascript

I just can't figure why this doesn't work for some odd values.
For example when trying to convert 22.68 to hours and minutes the output is 22:40.800000000000004 (Seconds shouldn't even appear)
if (str_HR_PER_WEEK.indexOf('.') > -1)
{
var str_HR_PER_WEEK_hrs = str_HR_PER_WEEK.substring(0 , str_HR_PER_WEEK.indexOf('.'));
var str_HR_PER_WEEK_mins = str_HR_PER_WEEK.substring(str_HR_PER_WEEK.indexOf('.') + 1);
var float_HR_PER_WEEK_mins = parseFloat("0." + (str_HR_PER_WEEK_mins), 10);
var float_HR_PER_WEEK_mins_actual = float_HR_PER_WEEK_mins * 60;
float_HR_PER_WEEK_mins_actual = float_HR_PER_WEEK_mins_actual.toString();
tables.CURRENT_EMPLOYEES.HOURS_PER_WEEK.value = getTwoDigitTime(str_HR_PER_WEEK_hrs) + ":" + getTwoDigitTime(float_HR_PER_WEEK_mins_actual);
}
else
{
tables.CURRENT_EMPLOYEES.HOURS_PER_WEEK.value = str_HR_PER_WEEK;
}

You have to ways to achieve that,
one, do the calculations yourself:
var decimalTimeString = "1.6578";
var decimalTime = parseFloat(decimalTimeString);
decimalTime = decimalTime * 60 * 60;
var hours = Math.floor((decimalTime / (60 * 60)));
decimalTime = decimalTime - (hours * 60 * 60);
var minutes = Math.floor((decimalTime / 60));
decimalTime = decimalTime - (minutes * 60);
var seconds = Math.round(decimalTime);
if(hours < 10)
{
hours = "0" + hours;
}
if(minutes < 10)
{
minutes = "0" + minutes;
}
if(seconds < 10)
{
seconds = "0" + seconds;
}
alert("" + hours + ":" + minutes + ":" + seconds);
Two, use built in function to convert to string and then to hh:mm:
var decimalTimeString = "1.6578";
var n = new Date(0,0);
n.setSeconds(+decimalTimeString * 60 * 60);
n.setMinutes(+decimalTimeString * 60);
var result = n.toTimeString().slice(0, 5);
document.write(result);

I've got a neat function to do just that:
function hoursToHHMM(hours) {
var h = String(Math.trunc(hours)).padStart(2, '0');
var m = String(Math.abs(Math.round((hours - h) * 60))).padStart(2, '0');
return h + ':' + m;
}
It handles negative values as a bonus.
Usage is trivial:
var hours = -7.33333;
console.log(hoursToHHMM(hours));
Results in: -07:20
You can play with it here: https://jsfiddle.net/r150c2me/

convert audio second time to minute and second format

var currentTime = audio.currentTime | 0;
var duration = audio.duration | 0;
it works but,
it shows the audio's total length and current time in only second format
i want to convert the default second value in Minute:Second format

Try this (lightly tested):
var seconds = currentTime % 60;
var foo = currentTime - seconds;
var minutes = foo / 60;
if(seconds < 10){
seconds = "0" + seconds.toString();
}
var fixedCurrentTime = minutes + ":" + seconds;

var currentTime = audio.currentTime | 0;
var duration = audio.duration | 0;
var minutes = "0" + Math.floor(duration / 60);
var seconds = "0" + (duration - minutes * 60);
var dur = minutes.substr(-2) + ":" + seconds.substr(-2);
var minutes = "0" + Math.floor(currentTime / 60);
var seconds = "0" + (currentTime - minutes * 60);
var cur = minutes.substr(-2) + ":" + seconds.substr(-2);

You can simply write the code yourself; it's not as if it's complicated or would ever change:
function pad(num, size) {
var s = num + '';
while (s.length < size) {
s = '0' + s;
}
return s;
}
function format_seconds(secs) {
return Math.floor(secs / 60) + ':' + (pad(secs % 60, 2));
}

dropping my own answer after 5 years and 9 months.
function() {
if(this.myAudio.readyState > 0) {
var currentTime = this.myAudio.currentTime;
var duration = this.myAudio.duration;
var seconds: any = Math.floor(duration % 60);
var foo = duration - seconds;
var min: any = foo / 60;
var minutes: any = Math.floor(min % 60);
var hours: any = Math.floor(min / 60);
if(seconds < 10){
seconds = "0" + seconds.toString();
}
if(hours > 0){
this.audioDuration = hours + ":" + minutes + ":" + seconds;
} else {
this.audioDuration = minutes + ":" + seconds;
}
}
}
I used typescript, hope this helps...

Calculate the Date difference in javascript with timer update

If you have two dates lets say dt1 and dt2.
How will you calculate the difference between them.
Here is the working example for your help:
var dt1;
var dt2;
$(document).ready(function () {
dt1 = new Date();
dt2 = new Date();
setInterval(function () {
dt2.setSeconds(dt2.getSeconds() + 1);
var diff = GetDateDiff(dt1, dt2);
$("#dtDIV").html(diff);
}, 1000);
});
function GetDateDiff(a, b) {
var msInDay = 1000 * 60 * 60 * 24;
var d1 = a.getTime();
var d2 = b.getTime();
var mlseconds = d2 - d1;
mlseconds = mlseconds / 1000;
var seconds = Math.floor(mlseconds % 60);
mlseconds = mlseconds / 60;
var minutes = Math.floor(mlseconds % 60);
mlseconds = mlseconds / 60;
var hours = Math.floor(mlseconds % 24);
var days = Math.floor(mlseconds / 24);
return days + ' days, ' + hours + ' hours, ' + minutes + ' minutes, and ' + seconds + ' seconds';
}
Full working example: http://goo.gl/5NE45o
Happy Coding !!!
Ambuj