# Sum of Time using javascript

How to of sum time in javascript

``````01:00:00
00:30:00
00:30:00
``````

I have time like above i want sum of given time like

``````sum of above time= 02:00:00
``````

if i use javascript method setHours(),setMinutes() these function replace old time and show newly added time like :

``````1. new Date( new Date(0, 0, 0, 00, 00, 00, 0)).setMinutes(30)
2. new Date(new Date( new Date(0, 0, 0, 00, 00, 00, 0)).setMinutes(30)).setMinutes(30);
``````

these above both condition result is same but i want here 00:30 + 00:30 = 01:00

Try this :

``````        var time1 = "01:00:00";
var time2 = "00:30:00";
var time3 = "00:30:00";

var hour=0;
var minute=0;
var second=0;

var splitTime1= time1.split(':');
var splitTime2= time2.split(':');
var splitTime3= time3.split(':');

hour = parseInt(splitTime1[0])+parseInt(splitTime2[0])+parseInt(splitTime3[0]);
minute = parseInt(splitTime1[1])+parseInt(splitTime2[1])+parseInt(splitTime3[1]);
hour = hour + minute/60;
minute = minute%60;
second = parseInt(splitTime1[2])+parseInt(splitTime2[2])+parseInt(splitTime3[2]);
minute = minute + second/60;
second = second%60;

Some functions to help you go back and forth between the formatted length of time and seconds as an integer:

``````function timestrToSec(timestr) {
var parts = timestr.split(":");
return (parts[0] * 3600) +
(parts[1] * 60) +
(+parts[2]);
}

if(num < 10) {
return "0" + num;
} else {
return "" + num;
}
}

function formatTime(seconds) {
].join(":");
}
``````

You can use them to achieve what you want:

``````time1 = "02:32:12";
time2 = "12:42:12";
formatTime(timestrToSec(time1) + timestrToSec(time2));
// => "15:14:24"
``````

If you want to use a `Date` object for this, you can, you just have to be sure to include the current value for the unit you're changing when adding to it, like so:

``````var dt = new Date(0, 0, 0, 0, 0, 0, 0);
dt.setHours(dt.getHours() + 1);      // For the 01:00
dt.setMinutes(dt.getMinutes() + 30); // For the first 00:30
dt.setMinutes(dt.getMinutes() + 30); // For the second 00:30

display("Hours: " + dt.getHours());
display("Minutes: " + dt.getMinutes());

function display(msg) {
var p = document.createElement("p");
p.innerHTML = String(msg);
document.body.appendChild(p);
}``````

Technically, of course, the first time you know `getHours` and `getMinutes` will return `0`, but for consistency, best to just always include them.

This solution is perfect:

``````function timestrToSec(timestr) {
var parts = timestr.split(":");
return (parts[0] * 3600) +
(parts[1] * 60) +
(+parts[2]);
}

if(num < 10) {
return "0" + num;
} else {
return "" + num;
}
}

function formatTime(seconds) {
].join(":");
}
``````

but there is a little bug in the last function "formatTime" !

``````return [pad(Math.floor(seconds/3600)%60), => return [pad(Math.floor(seconds/3600)),
``````

so without %60!! Becouse if i have to sum hour, it can be greater than 60 (H)

This work for me:

``````    function padnum(n){return n<10 ? '0'+n : n}

var time1 = "00:30";
var time2 = "00:60";

var minute=0;
var second=0;

var splitTime1= time1.split(':');
var splitTime2= time2.split(':');

minute = parseInt(parseInt(splitTime1[0]))+parseInt(splitTime2[0]);
second = parseInt(parseInt(splitTime1[1]))+parseInt(splitTime2[1]);

minute = minute + second/60;
minute =parseInt(minute);
second = second%60;

``````

Here is a function with error handling included.

Even though it's a big function it results in an useful one-liner. Just pass an array with values and you're good to go.

``````function sumMinutes(values) {

const validate = time => {
if (time > 59 || time < 0) {
throw new Error(
"Hours, minutes and seconds values have to be between 0 and 59."
);
}
return time;
};

const seconds = values
.map(e => validate(Number(e.split(":").reverse()[0])))
.reduce((a, b) => a + b);

let minutes = values
.map(e => Number(e.split(":").reverse()[1]))
.reduce((a, b) => a + b);

let hours = values
.map(e =>
e.split(":").reverse()[2] ? Number(e.split(":").reverse()[2]) : 0
)
.reduce((a, b) => a + b);

minutes *= 60;
hours *= 3600;

let result = new Date((hours + minutes + seconds) * 1000)
.toISOString()
.substr(11, 8);

return result.split(":").reverse()[2] === "00" ? result.slice(3) : result;
}

/* examples */
const seconds = ["00:03", "00:9"];
const mins = ["01:20", "1:23"];
const hours = ["00:03:59", "02:05:01"];
const mix = ["00:04:58", "10:00"];

console.log(sumMinutes(seconds)); //'00:12'
console.log(sumMinutes(mins)); //'02:43'
console.log(sumMinutes(hours)); //'02:09:00'
console.log(sumMinutes(mix)); //'14:58'
``````