Develop Reference

Calculating Time Until a Future Date - Trouble With Formatting Date Correctly In Variables

I'm trying to calculate the time between now (any time user runs script) and daylight savings (Nov 03, 2019, 2:00 AM).
I think I'm close but am having trouble getting the date variables to format and interact properly. What would the right definition for the variable dateTime be, or am I messing up with the variable daylightDate?
function daylightTime()
{
var today = new Date();
var date = today.getFullYear()+'-'+(today.getMonth()+1)+'-'+today.getDate();
var time = today.getHours() + ":" + today.getMinutes() + ":" + today.getSeconds();
var dateTime = date+' '+time;
document.getElementById("time1").innerHTML = "Current Date and Time: " +dateTime;
var daylightDate = new Date("November 03, 2019 02:00:00");
var delta = Math.abs(daylightDate - dateTime) / 1000;
// calculate (and subtract) whole days
var days = Math.floor(delta / 86400);
delta -= days * 86400;
// calculate (and subtract) whole hours
var hours = Math.floor(delta / 3600) % 24;
delta -= hours * 3600;
// calculate (and subtract) whole minutes
var minutes = Math.floor(delta / 60) % 60;
delta -= minutes * 60;
// what's left is seconds
var seconds = delta % 60; // in theory the modulus is not required
document.getElementById("time2").innerHTML = days + " " + hours + " " + minutes + " " + seconds;
}

Javascript multiple work hours calculate from date to now

I need a javascript like this one
// Calculate days since 7st May 2016
var initialDate = new Date(2016, 5, 7);
var now = Date.now();
var difference = now - initialDate;
var millisecondsPerDay = 24 * 60 * 60 * 1000;
var daysSince = Math.floor(difference / millisecondsPerDay);
// Write result to HTML
document.getElementById('days_since').innerHTML = daysSince;
<div id="days_since"></div>
but I would like to display hours and my work is eg. monday-friday from 10am to 6pm and every saturday from 11am to 3pm.
Any advice?

Hi please refer this http://jsfiddle.net/yentup/fKA9X/1/
JS
$(function(){
var calcNewYear = setInterval(function(){
date_future = new Date(new Date().getFullYear() +1, 0, 1);
date_now = new Date();
seconds = Math.floor((date_future - (date_now))/1000);
minutes = Math.floor(seconds/60);
hours = Math.floor(minutes/60);
days = Math.floor(hours/24);
hours = hours-(days*24);
minutes = minutes-(days*24*60)-(hours*60);
seconds = seconds-(days*24*60*60)-(hours*60*60)-(minutes*60);
$("#time").text("Time until new year:\nDays: " + days + " Hours: " + hours + " Minutes: " + minutes + " Seconds: " + seconds);
},1000);
});
and HTML
<div id="time"></div>

JavaScript date difference correction

I have a function that will calculate time between two date / time but I am having a small issue with the return.
Here is the way I collect the information.
Start Date
Start Time
Ending Date
Ending Time
Hours
And here is the function that calculates the dates and times:
function calculate (form) {
var d1 = document.getElementById("date1").value;
var d2 = document.getElementById("date2").value;
var t1 = document.getElementById("time1").value;
var t2 = document.getElementById("time2").value;
var dd1 = d1 + " " + t1;
var dd2 = d2 + " " + t2;
var date1 = new Date(dd1);
var date2 = new Date(dd2);
var sec = date2.getTime() - date1.getTime();
if (isNaN(sec)) {
alert("Input data is incorrect!");
return;
}
if (sec < 0) {
alert("The second date ocurred earlier than the first one!");
return;
}
var second = 1000,
minute = 60 * second,
hour = 60 * minute,
day = 24 * hour;
var hours = Math.floor(sec / hour);
sec -= hours * hour;
var minutes = Math.floor(sec / minute);
sec -= minutes * minute;
var seconds = Math.floor(sec / second);
var min = Math.floor((minutes * 100) / 60);
document.getElementById("result").value = hours + '.' + min;
}
If I put in todays date for both date fields and then 14:30 in the first time field and 15:35 in the second time field the result is shown as 1.8 and it should be 1.08
I didn't write this function but I am wondering if someone could tell me how to make that change?
Thank you.

If I understand correctly, the only issue you are having is that the minutes are not padded by zeroes. If this is the case, you can pad the value of min with zeroes using this little trick:
("00" + min).slice(-2)

I can't see why 15:35 - 14:30 = 1.08 is useful?
Try this instead:
function timediff( date1, date2 ) {
//Get 1 day in milliseconds
var one_day=1000*60*60*24;
// Convert both dates to milliseconds
var date1_ms = date1.getTime();
var date2_ms = date2.getTime();
// Calculate the difference in milliseconds
var difference_ms = date2_ms - date1_ms;
//take out milliseconds
difference_ms = difference_ms/1000;
var seconds = Math.floor(difference_ms % 60);
difference_ms = difference_ms/60;
var minutes = Math.floor(difference_ms % 60);
difference_ms = difference_ms/60;
var hours = Math.floor(difference_ms % 24);
var days = Math.floor(difference_ms/24);
return [days,hours,minutes,seconds];
}
function calculate (form) {
var d1 = document.getElementById("date1").value;
var d2 = document.getElementById("date2").value;
var t1 = document.getElementById("time1").value;
var t2 = document.getElementById("time2").value;
var dd1 = d1 + " " + t1;
var dd2 = d2 + " " + t2;
var date1 = new Date(dd1);
var date2 = new Date(dd2);
var diff = timediff(date1, date2);
document.getElementById("result").value = diff[1] + ':' + diff[2];
}

Verify if number of minutes is less than 10 and if it is then append an additional zero in front. Follow similar approach for seconds.

String to date conversion not working correctly in Javascript

I need to get time difference in this format: "HH:MM:SS" using a Javascript.
I have tried this:
var diff = Date.parse( time2) - Date.parse( time1 );
var total_time = (diff / 1000 / 60 / 60) + ":" + (diff / 1000 / 60) + ":" + (diff / 1000);
and this:
var diff = new Date( time2) - new Date( time1 );
var total_time = (diff / 1000 / 60 / 60) + ":" + (diff / 1000 / 60) + ":" + (diff / 1000);
These are the values of time2 and time1:
time1: "2012-11-07 15:20:32.161"
time2: "2012-11-07 17:55:41.451"
And result I am getting in both cases is:
total_time= 0.5250819444444444:31.504916666666666:1890.295
Which you can see is not correct

I think you are getting wrong diff value because of the millisecond part in the date delimited by .. Its not being accepted correctly by the data parser.
Try using the date and time part excluding the milliseconds as below:
var diff = Date.parse(time2.split(".")[0]) - Date.parse( time1.split(".")[0]);
Also while you are getting wrong difference diff, your time computation is also wrong.
It should be:
var second = Math.floor(diff /1000);
//convert the seconds into minutes and remainder is updated seconds value
var minute = Math.floor(second /60);
second = second % 60;
//convert the minutes into hours and remainder is updated minutes value
var hour = Math.floor(minute/60);
minute = minute %60;
var total_time= hour+":" minute+":"+second;

You forgot to remove the number of milliseconds you already calculated from diff. Here is a very verbose example on how you do it in a propper way.
var time1 = "2012-11-07 15:20:32.161",
time2 = "2012-11-07 17:55:41.451",
SECOND = 1000,
MINUTE = SECOND* 60,
HOUR = MINUTE* 60;
var diff = new Date(time2) - new Date(time1);
var hours = Math.floor(diff / HOUR); // Calculate how many times a full hour fits into diff
diff = diff - (hours * HOUR); // Remove hours from difference, we already caluclated those
var minutes = Math.floor(diff / MINUTE); // Calculate how many times a full minute fits into diff
diff = diff - (minutes * MINUTE); // Remove minutes from difference
var seconds = Math.floor(diff / SECOND); // As before
diff = diff - (seconds * SECOND);
var rest = diff;
var total_time = hours + ":" + minutes + ":" + seconds + " " + rest ;
DEMO

Calculating time diference in JavaScript (days+hours+minutes+seconds)

lol sorry i posted it accidentally
I'm new to JavaScript and i'm trying to make a simple countdown script that should show the difference between the end date and today's server date.
here is a great example of what i'm trying to do http://moblog.bradleyit.com/2009/06/javascripting-to-find-difference.html
The only thing i want to add is another variable with a calculated seconds. How can i do that?
Here is the code:
var today = new Date();
var Christmas = new Date("12-25-2009");
var diffMs = (Christmas - today); // milliseconds between now & Christmas
var diffDays = Math.round(diffMs / 86400000); // days
var diffHrs = Math.round((diffMs % 86400000) / 3600000); // hours
var diffMins = Math.round(((diffMs % 86400000) % 3600000) / 60000); // minutes
alert(diffDays + " days, " + diffHrs + " hours, " + diffMins + " minutes until Christmas 2009 =)");

You have two issues with this code:
1: You need to use a date that will be accepted across browsers so it needs to be formatted with / instead of -.
2: You are rounding, which when rounding up will give you inaccurate numbers. All numbers need to be rounded down. Here is a function do do so:
var roundDown = function(num){
var full = num.toString();
var reg = /([\d]+)/i;
var res = reg.exec(full);
return res[1];
}
So your final code should look like this:
var roundDown = function(num){
var full = num.toString();
var reg = /([\d]+)/i;
var res = reg.exec(full);
return res[1];
}
var today = new Date(); // date and time right now
var goLive = new Date("06/01/2013"); // target date
var diffMs = (goLive - today); // milliseconds between now & target date
var diffDays = roundDown(diffMs / 86400000); // days
var diffHrs = roundDown((diffMs % 86400000) / 3600000); // hours
var diffMins = roundDown(((diffMs % 86400000) % 3600000) / 60000); // minutes
var diffSecs = roundDown((((diffMs % 86400000) % 3600000) % 60000) / 1000 ); // seconds

var endDate = new Date(year, month, day, hours, minutes, seconds, milliseconds);
var today = Date.now()
var timeLeft = endDate - today // timeLeft would be in milliseconds
// Parse this into months, days, hours, ...
Put this in a function and set it up to be called every second or so using setInterval.

This should get you started with the JavaScript date object and it's associated methods.
http://www.w3schools.com/jsref/jsref_obj_date.asp
Also, look up the setInterval() method, that will allow you to fire code in set intervals (for example, updating the countdown text).