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How to add milliseconds with JavaScript

I'm adding two time strings in order to get single time string in h:m:s format with milliseconds to be added as well.
I only managed until the seconds. Now I also want to add the milliseconds
I also want to add more than two time strings, that is, more than two parameters
function addTimes (startTime, endTime) {
var times = [ 0, 0, 0 ]
var max = times.length
var a = (startTime || '').split(':')
var b = (endTime || '').split(':')
// normalize time values
for (var i = 0; i < max; i++) {
a[i] = isNaN(parseInt(a[i])) ? 0 : parseInt(a[i])
b[i] = isNaN(parseInt(b[i])) ? 0 : parseInt(b[i])
}
// store time values
for (var i = 0; i < max; i++) {
times[i] = a[i] + b[i]
}
var hours = times[0]
var minutes = times[1]
var seconds = times[2]
if (seconds >= 60) {
var m = (seconds / 60) << 0
minutes += m
seconds -= 60 * m
}
if (minutes >= 60) {
var h = (minutes / 60) << 0
hours += h
minutes -= 60 * h
}
return ('0' + hours).slice(-2) + ':' + ('0' + minutes).slice(-2) + ':' + ('0' + seconds).slice(-2)
}
alert(addTimes('9:10:10', '1:0:0'));

You can just extend your existing function to handle milliseconds the same way it's currently handling minutes and seconds, just with a factor of 1,000 instead of 60.
function addTimes(startTime, endTime) {
// Add element for milliseconds to times
var times = [0, 0, 0, 0];
var max = times.length;
// Split on ':' and '.'
var a = (startTime || '').split(/[:.]/);
var b = (endTime || '').split(/[:.]/);
// normalize time values
for (var i = 0; i < max; i++) {
a[i] = isNaN(parseInt(a[i])) ? 0 : parseInt(a[i]);
b[i] = isNaN(parseInt(b[i])) ? 0 : parseInt(b[i]);
}
// store time values
for (var i = 0; i < max; i++) {
times[i] = a[i] + b[i];
}
var hours = times[0];
var minutes = times[1];
var seconds = times[2];
// Add variable for milliseconds
var milliseconds = times[3];
// Add milliseconds first
if (milliseconds >= 1000) {
var s = (milliseconds / 1000) << 0;
seconds += s;
milliseconds -= 1000 * s;
}
// Continue as for original
if (seconds >= 60) {
var m = (seconds / 60) << 0;
minutes += m;
seconds -= 60 * m;
}
if (minutes >= 60) {
var h = (minutes / 60) << 0;
hours += h;
minutes -= 60 * h;
}
return ('0' + hours).slice(-2) + ':' +
('0' + minutes).slice(-2) + ':' +
('0' + seconds).slice(-2) + '.' +
// Add milliseconds to return
('00' + milliseconds).slice(-3);
}
console.log(addTimes('9:10:10.500', '1:0:55.501'));
I'd simplify things a bit and do away with the if statements and just do the overflow thing every time. Also, it can be made a bit more tolerant of partial strings and invalid values, e.g.
/* Add times in format h:mm:ss.sss
** return total time in same format
** Accepts partial times, first digit treated as hours
** e.g. 1:30 is equivalent to 1:30:00.000
** Invalid and missing parts treated as 0 (zero)
** #param {string} timeA : time in format h:mm:ss.sss
** #param {string} timeB : time in format h:mm:ss.sss
** #returns {string} sum of timeA and timeB in format h:mm:ss.sss
*/
function addTime(timeA, timeB) {
// Pad function for numbers less than 100
let z = (n, len) => String(n).padStart(len, '0');
// Split timestamps into parts as numbers, NaN => 0
let parts = s => String(s).split(/[:.]/).map(v => Number(v) || 0);
let [aH, aM, aS, aMs] = parts(timeA);
let [bH, bM, bS, bMs] = parts(timeB);
// Initialise total values, tx is just a placeholder
let tH = 0, tM = 0, tS = 0, tMs = 0, tX;
// Helper to add time values - omitting f just adds a + b
let factorSum = (a, b, f) => {
let t = (a || 0) + (b || 0);
return f? [t / f | 0, t % f] : [0, t];
};
// Add parts in order using helper
[tS, tMs] = factorSum(aMs, bMs, 1000);
[tM, tS] = factorSum(aS, bS + tS, 60);
[tH, tM] = factorSum(aM, bM + tM, 60);
[tX, tH] = factorSum(aH, bH + tH);
// Return formatted result
return tH + ':' + z(tM,2) + ':' + z(tS,2) + '.' + z(tMs,3);
}
// No overflow
console.log(addTime('1:01:01.001', '2:02:02.200')); // 3:03:03.201
// Overflow mins, secs, milliseconds
console.log(addTime('1:59:59.999', '0:00:00.001')); // 2:00:00.000
// Partial times
console.log(addTime('1', '2:30:1')); // 3:30:01.000
// Missing parameter treated as 0
console.log(addTime()); // 0:00:00.000
console.log(addTime('1:15')); // 1:15:00.000
// Invalid parts treated as zero
console.log(addTime('1:15', 'foo')); // 1:15:00.000
console.log(addTime('1:15', '2:blah:23.001')); // 3:15:23.001
If I could use a addition assignment += with destructuring it could be simpler, but that's not possible yet. :-)

Get timeslots from starting and ending time

I want timeslots from starting time and ending time with a given interval. also need to check that if the provided date is same as today's date then start time would be the current time of particular region. (like if time is 10:12 then we need to start from 10:30 and if time is 10:36 then opt for 11:00 (i.e. from 1 minute to 29 we should opt 30 minutes and from 31 to 59 we should opt 00) ).
So, how can I achieve that using given values below?
Input:
let date = "20-07-2019"
let startTime = "10:00";
let endtime = "14:00";
let interval = 60; // in minutes
Expected Output:
["10:00 - 11:00", "11:00- 12:00" , "12:00- 13:00", "13:00 - 14:00"]
My code:
let parseTime = (s) => {
let c = s.split(':');
return parseInt(c[0]) * 60 + parseInt(c[1]);
}
let convertHours = (mins) => {
let hour = Math.floor(mins / 60);
mins = mins % 60;
let converted = pad(hour, 2) + ':' + pad(mins, 2);
return converted;
}
let pad = (str, max) => {
str = str.toString();
return str.length < max ? pad("0" + str, max) : str;
}
let calculate_time_slot = (start_time, end_time, interval) => {
let i, formatted_time;
let time_slots = new Array();
for (let i = start_time; i <= end_time; i = i + interval) {
formatted_time = convertHours(i);
time_slots.push(formatted_time);
}
return time_slots;
}
let date = "20-07-2019"
let startTime = "10:00";
let endTime = "14:00";
let interval = 60; // in minutes
start_time = parseTime(startTime)
end_time = parseTime(endTime)
let times_ara = calculate_time_slot(start_time, end_time, interval);
console.log(times_ara);

I'd change the for loop to a while, then increment for the interval in the loop so you have both the start and end times in the loop, e.g.
let parseTime = (s) => {
let c = s.split(':');
return parseInt(c[0]) * 60 + parseInt(c[1]);
}
let convertHours = (mins) => {
let hour = Math.floor(mins / 60);
mins = mins % 60;
let converted = pad(hour, 2) + ':' + pad(mins, 2);
return converted;
}
let pad = (str, max) => {
str = str.toString();
return str.length < max ? pad("0" + str, max) : str;
}
let calculate_time_slot = (start_time, end_time, interval) => {
let i, formatted_time;
let time_slots = new Array();
// Round start and end times to next 30 min interval
start_time = Math.ceil(start_time / 30) * 30;
end_time = Math.ceil(end_time / 30) * 30;
// Start and end of interval in the loop
while (start_time < end_time) {
let t = convertHours(start_time) + ' - ' + (convertHours(start_time += interval));
time_slots.push(t);
}
return time_slots;
}
let date = "20-07-2019"
let startTime = "10:00";
let endtime = "14:00";
let interval = 60; // in minutes
let end_time = parseTime(endtime)
let start_time = parseTime(startTime)
let times_ara = calculate_time_slot(start_time, end_time, interval);
console.log(times_ara);
There's quite a bit of other stuff I'd change too, but that's the minimum to get your desired result.
Oh, I added a bit to round to the next 30 minute interval 'cos that's what you said you wanted too.

Your function seems to generate the required values you just need to change how they are represented, here is a way of doing that:
let time_slots = ["10:00", "11:00", "12:00", "13:00", "14:00"];
time_slots = time_slots.reduce((a, c, i, arr) => {
if (i < arr.length - 1) {
a.push(`${c} - ${arr[i + 1]}`);
}
return a;
}, []);
console.log(time_slots);

This is the shortest I got.
let calculate_time_slot = (start_time, end_time, interval) => {
const timeSlots = [];
for (let i = start_time; i < end_time; i += interval) {
const formattedBegin = convertHours(i);
const formattedEnd = convertHours(i + interval);
timeSlots.push(formattedBegin + ' - ' + formattedEnd);
}
return timeSlots;
}
Runnable snippet:
let parseTime = (s) => {
let c = s.split(':');
return parseInt(c[0]) * 60 + parseInt(c[1]);
}
let convertHours = (mins) => {
let hour = Math.floor(mins / 60);
mins = mins % 60;
let converted = pad(hour, 2) + ':' + pad(mins, 2);
return converted;
}
let pad = (str, max) => {
str = str.toString();
return str.length < max ? pad("0" + str, max) : str;
}
let calculate_time_slot = (start_time, end_time, interval) => {
const timeSlots = [];
for (let i = start_time; i < end_time; i += interval) {
const formattedBegin = convertHours(i);
const formattedEnd = convertHours(i + interval);
timeSlots.push(formattedBegin + ' - ' + formattedEnd);
}
return timeSlots;
}
let date = "20-07-2019"
let startTime = "10:00";
let endTime = "14:00";
let interval = 60; // in minutes
start_time = parseTime(startTime)
end_time = parseTime(endTime)
let times_ara = calculate_time_slot(start_time, end_time, interval);
console.log(times_ara);

Convert seconds to days, hours, minutes and seconds

I have a Javascript timing event with an infinite loop with a stop button.
It will display numbers when start button is click.Now I want this numbers converted to something like 4 hours, 3 minutes , 50 seconds
var c = 0;
var t;
var timer_is_on = 0;
function timedCount() {
document.getElementById('txt').value = c;
c = c + 1;
t = setTimeout(function() {
timedCount()
}, 1000);
}
function doTimer() {
if (!timer_is_on) {
timer_is_on = 1;
timedCount();
}
}
function stopCount() {
clearTimeout(t);
timer_is_on = 0;
}
$(".start").on("click", function() {
//var start = $.now();
//alert(start);
//console.log(start);
doTimer();
$(".end").show();
$(".hide_div").show();
});
$(".end").on("click", function() {
stopCount();
});
.hide_div {
display: none;
}
.end {
display: none;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p class="start">Start</p>
<p class="end">End</p>
<p class="hide_div">
<input type="text" id="txt" />//display numbers eg 12345
</p>
How to convert numbers like 123456 to 1 day, 4 hours, 40 min, 45 seconds?

I suggest doing this way!:
function secondsToDhms(seconds) {
seconds = Number(seconds);
var d = Math.floor(seconds / (3600*24));
var h = Math.floor(seconds % (3600*24) / 3600);
var m = Math.floor(seconds % 3600 / 60);
var s = Math.floor(seconds % 60);
var dDisplay = d > 0 ? d + (d == 1 ? " day, " : " days, ") : "";
var hDisplay = h > 0 ? h + (h == 1 ? " hour, " : " hours, ") : "";
var mDisplay = m > 0 ? m + (m == 1 ? " minute, " : " minutes, ") : "";
var sDisplay = s > 0 ? s + (s == 1 ? " second" : " seconds") : "";
return dDisplay + hDisplay + mDisplay + sDisplay;
}

Use Math like this way, Second param in parseInt is for base, which is optional
var seconds = parseInt(123456, 10);
var days = Math.floor(seconds / (3600*24));
seconds -= days*3600*24;
var hrs = Math.floor(seconds / 3600);
seconds -= hrs*3600;
var mnts = Math.floor(seconds / 60);
seconds -= mnts*60;
console.log(days+" days, "+hrs+" Hrs, "+mnts+" Minutes, "+seconds+" Seconds");
Your given seconds 123456 would be 1 days, 10 Hrs, 17 Minutes, 36 Seconds not 1 days, 4 Hrs, 40 Minutes, 45 Seconds

function countdown(s) {
const d = Math.floor(s / (3600 * 24));
s -= d * 3600 * 24;
const h = Math.floor(s / 3600);
s -= h * 3600;
const m = Math.floor(s / 60);
s -= m * 60;
const tmp = [];
(d) && tmp.push(d + 'd');
(d || h) && tmp.push(h + 'h');
(d || h || m) && tmp.push(m + 'm');
tmp.push(s + 's');
return tmp.join(' ');
}
// countdown(3546544) -> 41d 1h 9m 4s
// countdown(436654) -> 5d 1h 17m 34s
// countdown(3601) -> 1h 0m 1s
// countdown(121) -> 2m 1s

My solution with map() and reduce():
const intervalToLevels = (interval, levels) => {
const cbFun = (d, c) => {
let bb = d[1] % c[0],
aa = (d[1] - bb) / c[0];
aa = aa > 0 ? aa + c[1] : '';
return [d[0] + aa, bb];
};
let rslt = levels.scale.map((d, i, a) => a.slice(i).reduce((d, c) => d * c))
.map((d, i) => ([d, levels.units[i]]))
.reduce(cbFun, ['', interval]);
return rslt[0];
};
const TimeLevels = {
scale: [24, 60, 60, 1],
units: ['d ', 'h ', 'm ', 's ']
};
const secondsToString = interval => intervalToLevels(interval, TimeLevels);
If you call secondsToString(123456), you can get "1d 10h 17m 36s "

Here is my solution, a simple function that will round to the nearest second!
var returnElapsedTime = function(epoch) {
//We are assuming that the epoch is in seconds
var hours = epoch / 3600,
minutes = (hours % 1) * 60,
seconds = (minutes % 1) * 60;
return Math.floor(hours) + " hours, " + Math.floor(minutes) + " minutes, " + Math.round(seconds) + " seconds";
}

Came up with my own variation to some of the solutions suggested in this thread.
if (!Number.prototype.secondsToDHM) {
Number.prototype.secondsToDHM = function() {
const secsPerDay = 86400;
const secsPerHour = 3600;
const secsPerMinute = 60;
var seconds = Math.abs(this);
var minus = (this < 0) ? '-' : '';
var days = Math.floor(seconds / secsPerDay);
seconds = (seconds % secsPerDay);
var hours = Math.floor(seconds / secsPerHour);
seconds = (seconds % secsPerHour);
var minutes = Math.floor(seconds / secsPerMinute);
seconds = (seconds % secsPerMinute);
var sDays = new String(days).padStart(1, '0');
var sHours = new String(hours).padStart(2, '0');
var sMinutes = new String(minutes).padStart(2, '0');
return `${minus}${sDays}D ${sHours}:${sMinutes}`;
}
}
var a = new Number(50000).secondsToDHM();
var b = new Number(100000).secondsToDHM();
var c = new Number(200000).secondsToDHM();
var d = new Number(400000).secondsToDHM();
console.log(a);
console.log(b);
console.log(c);
console.log(d);

This answer builds upon on Andris' approach to this question, but it doesn't have trailing commas if lesser units are not present.
It also borrows from this answer dealing with joining array values only if truthy:
https://stackoverflow.com/a/19903063
I'm not a javascript god and it's probably horribly over-engineered, but hopefully readable and correct!
function sformat(s) {
// create array of day, hour, minute and second values
var fm = [
Math.floor(s / (3600 * 24)),
Math.floor(s % (3600 * 24) / 3600),
Math.floor(s % 3600 / 60),
Math.floor(s % 60)
];
// map over array
return $.map(fm, function(v, i) {
// if a truthy value
if (Boolean(v)) {
// add the relevant value suffix
if (i === 0) {
v = plural(v, "day");
} else if (i === 1) {
v = plural(v, "hour");
} else if (i === 2) {
v = plural(v, "minute");
} else if (i === 3) {
v = plural(v, "second");
}
return v;
}
}).join(', ');
}
function plural(value, unit) {
if (value === 1) {
return value + " " + unit;
} else if (value > 1) {
return value + " " + unit + "s";
}
}
console.log(sformat(60)); // 1 minute
console.log(sformat(3600)); // 1 hour
console.log(sformat(86400)); // 1 day
console.log(sformat(8991)); // 2 hours, 29 minutes, 51 seconds
If you needed to convey the duration more 'casually' in words, you could also do something like:
var remaining_duration = sformat(117);
// if a value is returned, add some prefix and suffix
if (remaining_duration !== "") {
remaining_duration = "about " + remaining_duration + " left";
}
$(".remaining_duration").text(remaining_duration);
// returns 'about 1 minute, 57 seconds left'

I further tweaked the code by Svetoslav as follows:
function convertSecondsToReadableString(seconds) {
seconds = seconds || 0;
seconds = Number(seconds);
seconds = Math.abs(seconds);
const d = Math.floor(seconds / (3600 * 24));
const h = Math.floor(seconds % (3600 * 24) / 3600);
const m = Math.floor(seconds % 3600 / 60);
const s = Math.floor(seconds % 60);
const parts = [];
if (d > 0) {
parts.push(d + ' day' + (d > 1 ? 's' : ''));
}
if (h > 0) {
parts.push(h + ' hour' + (h > 1 ? 's' : ''));
}
if (m > 0) {
parts.push(m + ' minute' + (m > 1 ? 's' : ''));
}
if (s > 0) {
parts.push(s + ' second' + (s > 1 ? 's' : ''));
}
return parts.join(', ');
}

Short answer:
var s = (Math.floor(123456/86400) + ":" + (new Date(123456 * 1000)).toISOString().substr(11, 8)).split(":");
console.log(`${s[0]} days, ${s[1]} hours, ${s[2]} minutes, ${s[3]} seconds` )
Edit:
Let me break it down in parts :
Math.floor(123456/86400)
86400 is the the total seconds in a day (60 seconds * 60 minutes * 24 hours). Dividing the inputted seconds by this value gives us number of days. We just need the whole part so we use Math.floor because the fractional piece is handled by this part:
(new Date(123456 * 1000)).toISOString().substr(11, 8)
the explanation can be found here:
Convert seconds to HH-MM-SS with JavaScript?
It just outputs hh:mm:ss, no days. So the first part and this part is a perfect combination
We concatenate using a colon (:) as a separator. The string looks like this:
'1:10:17:36'
We split it into an array with .split(":");. Then finally, we format the elements of the array for the desired output.

I've tweaked the code that Andris posted https://stackoverflow.com/users/3564943/andris
// https://stackoverflow.com/questions/36098913/convert-seconds-to-days-hours-minutes-and-seconds
function app_ste_36098913_countdown_seconds_to_hr(seconds) {
seconds = seconds || 0;
seconds = Number(seconds);
seconds = Math.abs(seconds);
var d = Math.floor(seconds / (3600*24));
var h = Math.floor(seconds % (3600*24) / 3600);
var m = Math.floor(seconds % 3600 / 60);
var s = Math.floor(seconds % 60);
var parts = new Array();
if (d > 0) {
var dDisplay = d > 0 ? d + ' ' + (d == 1 ? "day" : "days") : "";
parts.push(dDisplay);
}
if (h > 0) {
var hDisplay = h > 0 ? h + ' ' + (h == 1 ? "hour" : "hours") : "";
parts.push(hDisplay)
}
if (m > 0) {
var mDisplay = m > 0 ? m + ' ' + (m == 1 ? "minute" : "minutes") : "";
parts.push(mDisplay)
}
if (s > 0) {
var sDisplay = s > 0 ? s + ' ' + (s == 1 ? "second" : "seconds") : "";
parts.push(sDisplay)
}
return parts.join(', ', parts);
}

You will probably find using epoch timestamps more straightforward: As detailed in Convert a Unix timestamp to time in JavaScript, the basic method is like so:
<script>
// Create a new JavaScript Date object based on the timestamp
// multiplied by 1000 so that the argument is in milliseconds, not seconds.
var date1 = new Date();
alert ('easy trick to waste a few seconds...' + date1);
// var date = date2 - date1;
// Hours part from the timestamp
var hours1 = date1.getHours();
// Minutes part from the timestamp
var minutes1 = "0" + date1.getMinutes();
// Seconds part from the timestamp
var seconds1 = "0" + date1.getSeconds();
var date2 = new Date();
// Hours part from the timestamp
var hours2 = date2.getHours();
// Minutes part from the timestamp
var minutes2 = "0" + date2.getMinutes();
// Seconds part from the timestamp
var seconds2 = "0" + date2.getSeconds();
// Will display time in 10:30:23 format
// var formattedTime = hours + ':' + minutes.substr(-2) + ':' + seconds.substr(-2);
var elapsedHrs = hours2 - hours1;
var elapsedMin = minutes2.substr(-2) -minutes1.substr(-2);
var elapsedSec = seconds2.substr(-2) - seconds1.substr(-2);
var elapsedTime = elapsedHrs + ' hours, ' + elapsedMin + ' minutes, ' + elapsedSec + ' seconds';
alert ('time between timestamps: ' + elapsedTime);
</script>
Be warned that this script needs some work since for now it will give negative values for things like date1 = 12:00:00 and date2 = 12:00:05, but I'll leave that to you fo now.
You should rewrite your code to take a timestamp ( var x = new Date(); ) at the start of your timer and one whenever you are done/want to check elapsed time, and subtract the two before parsing out elapsed seconds, minutes, hours etc as required.

This is my take at the question, even if it is an old topic.
You can use a loop to compute everything for you :
function time_remaining(date1, date2) {
let seconds = (date2 - date1) / 1000
let units = ["years", "days", "h", "min", "s"]
let limit_units = [365, 24, 60, 60, 1]
const reducer = (accumulator, curr) => accumulator * curr;
let time = []
for (let i = 0; i < units.length; i++) {
let divisor = limit_units.slice(i).reduce(reducer)
let value = Math.floor(seconds / divisor)
seconds = seconds - value * divisor
time.push(value)
}
return clean_time(time, units)
}
// at this point, you have your answer. However,
// we can improve the result by removing all none
// significative null units (i.e, if your countdown is
// only about hours, minutes and seconds, it is not
// going to include years and days.)
function clean_time(time, units) {
time = time.reverse()
while (time[time.length - 1] == 0) {
time.pop()
}
return [time.reverse(), units.slice(-time.length)]
}
let date1 = Date.parse("2023-07-09T17:50:33")
console.log(time_remaining(Date.now(), date1))

change date format function

I am trying to change a date format, would you please help me out to change the date format into this Mon, 12 Feb 2016 11:00?
Here is the code below:
function nicetime(a, out) {
var d = Math.round((+new Date - a) / 1000),
fuzzy = '',
n = 'mins',
d = d < 0 ? 0 : d;
if (out == 1) {
return d;
} else if (out == 0) {
var chunks = new Array();
chunks[0] = [60 * 60 * 24 * 365, 'year', 'years'];
chunks[1] = [60 * 60 * 24 * 30, 'month', 'months'];
chunks[2] = [60 * 60 * 24 * 7, 'week', 'weeks'];
chunks[3] = [60 * 60 * 24, 'day', 'days'];
chunks[4] = [60 * 60, 'hr', 'hrs'];
chunks[5] = [60, 'min', 'mins'];
var i = 0,
j = chunks.length;
for (i = 0; i < j; i++) {
s = chunks[i][0];
if ((xj = Math.floor(d / s)) != 0) {
n = xj == 1 ? chunks[i][1] : chunks[i][2];
break;
}
}
fuzzy += xj == 1 ? '1 ' + n : xj + ' ' + n;
if (i + 1 < j) {
s2 = chunks[i + 1][0];
if (((xj2 = Math.floor((d - (s * xj)) / s2)) != 0)) {
n2 = (xj2 == 1) ? chunks[i + 1][1] : chunks[i + 1][2];
fuzzy += (xj2 == 1) ? ' + 1 ' + n2 : ' + ' + xj2 + ' ' + n2;
}
}
fuzzy += ' ago';
return fuzzy;
}
}

Suppose , your date is "February 04, 2011 19:00:00"
function formatDate(date) {
var d = new Date(date);
var hh = d.getHours();
var m = d.getMinutes();
var s = d.getSeconds();
var dd = "AM";
var h = hh;
if (h >= 12) {
h = hh-12;
dd = "PM";
}
if (h == 0) {
h = 12;
}
m = m<10?"0"+m:m;
s = s<10?"0"+s:s;
/* if you want 2 digit hours:
h = h<10?"0"+h:h; */
var pattern = new RegExp("0?"+hh+":"+m+":"+s);
var replacement = h+":"+m;
/* if you want to add seconds
replacement += ":"+s; */
replacement += " "+dd;
return date.replace(pattern,replacement);
}
alert(formatDate("February 04, 2011 12:00:00"));

Averaging Times using Javascript

I am building an app using Phonegap and JQuery.
The app stores ( using window.localStorage ) a set of times (no more than 10) in the format.
HH:MM:SS.mm
There are a number of 'Zero' times in the list eg '00:00:00.00' which iphonegap, javascript
eliminate using..
function removeA(arr){
var what, a= arguments, L= a.length, ax;
while(L> 1 && arr.length){
what= a[--L];
while((ax= arr.indexOf(what))!= -1){
arr.splice(ax, 1);
}
}
return arr;
}
scores.sort();
removeA(scores,'00:00:00.00');
so that i'm left with the fastest time first, and only the times that have a value.
I need to produce from the remaining values the average of those times.
eg: 00:00:03.00
00:00:05.00
00:00:02.00
00:00:06.00
= 00:00:04.00
thanks in advance :)

var times= [ '00:00:03.00', '00:00:05.00', '00:00:02.00', '00:00:06.00'],
date = 0,
result = '';
function offsetify(t){
return t < 10 ? '0' + t : t;
}
for(var x = 0; x < times.length; x++ ) {
var tarr = times[x].split(':');
date += new Date(0, 0, 0, tarr[0], tarr[1], tarr[2].split('.')[0], tarr[2].split('.')[1]).getTime();
}
var avg = new Date(date/times.length);
result = offsetify(avg.getHours()) + ':' + offsetify(avg.getMinutes()) + ':' + offsetify(avg.getSeconds()) + '.' + offsetify(avg.getMilliseconds());
DEMO

if you are going to also have millisecond values and you want to consider them, then convert the times into millisecond. Now, add them and divide them by the number of records. Else, convert everything to seconds and find the average - you get the answer in seconds, of course.
The conversion is quite simple if take little time to think over it. Here's how to convert.
To milliseconds:
function convertToMS(timeStr) { // timeStr in format 'HH:MM:SS.mm'
var I = parseInt; // for brevity
var t = timeStr,
h = I( t.substr(0,2) ),
m = I( t.substr(3,2) ),
s = I( t.substr(6,2) ),
ms = I( t.substr(9,2) );
return h * 3600000 + m * 60000 + s * 1000 + ms;
}
To seconds:
function convertToS(timeStr) { // timeStr in format 'HH:MM:SS[.mm]' -- .mm is ignored.
var I = parseInt; // for brevity
var t = timeStr,
h = I( t.substr(0,2) ),
m = I( t.substr(3,2) ),
s = I( t.substr(6,2) );
return h * 3600 + m * 60 + s;
}
After the conversion's done, add them up and find the average.
UPDATE:
To convert back to the format 'HH:MM:SS.mm', we change back the time into 'chunks' of hours, minutes, seconds and (if applicable) milliseconds.
function chunkifyFromSec(time) { // time in s
var t = "",
h = Math.floor(time / 3600),
m = Math.floor( (t - (h * 3600)) / 60 ),
s = t - (h * 3600) - (m * 60);
return {
HH: h, MM: m, SS: s, mm: 0
};
}
function chunkifyFromMS(time) { // time in ms
var t = "",
h = Math.floor(time / 3600000),
m = Math.floor( (t - (h * 3600000)) / 60000 ),
s = Math.floor( (t - (h * 3600000) - (m * 60000)) / 1000 ),
mm = t - (h * 3600000) - (m * 600000) - (s * 1000);
return {
HH: h, MM: m, SS: s, mm: mm
};
}
Then, we return the string in the format 'HH:MM:SS.mm' using this:
function toTimeStr(chunks) {
return
(chunks.HH < 0 ? '0' : '') + chunks.HH + ":"
+= (chunks.MM < 0 ? '0' : '') + chunks.MM + ":"
+= (chunks.SS < 0 ? '0' : '') + chunks.SS + "."
+= (chunks.mm < 0 ? '0' : '') + chunks.mm
}

I don't have much experience with Javascript so I might have some syntax errors but I think you could do something like
var i = 0;
var totalTime = 0.0;
for (i=0; i < scores.length; i++) {
var hours = parseFloat(scores[i].substring(0, 2)); //get numeric value for hours
var minutes = parseFloat(scores[i].substring(3,5)); //get numeric value for minutes
var seconds = parseFloat(scores[i].substring(6)); //get numeric for the seconds
var time = ((hours * 60) + minutes) * 60 + seconds; //60 minutes in an hour, 60 seconds in a minute
totalTime += time;
}
var avgTime = totalTime/scores.length;
var avgHours = Math.floor(avgTime / 3600); //60*60
var avgHoursStr = String(avgHours);
var avgMinutes = Math.floor((avgTime % 3600) / 60); //mod to get rid of the hours
var avgMinutesStr = String(avgMinutes);
var avgSeconds = avgTime - avgHours*3600 - avgMinutes*60; //get the remainder. Can't use mod due to decimal
var avgSeconds = String(avgSeconds);
//Concat strings. Add the ":" spacers. Where necessary, add leading 0
var avgStr = (avgHoursStr.length > 1 ? "" : "0") + avgHoursStr + ":" + (avgMinutesStr.length > 1 ? "" : "0") + avgMinuteStr + ":" + avgSecondsStr;
[EDIT - Thanks to Parth Thakkar for point out my problem]

To return the answer in milliseconds or seconds:
var times = ["00:00:03.00", "00:00:05.00", "00:00:02.00", "00:00:06.00"];
function averageTimes(times,unit) {
if (!times) {
return false;
}
else {
var totalMilliseconds = 0, hours, minutes, seconds, milliseconds, parts;
for (var i = 0, len = times.length; i < len; i++) {
parts = times[i].split(':');
hours = parseInt(parts[0], 10) * 3600000;
minutes = parseInt(parts[1], 10) * 60000;
seconds = parseInt(parts[2].split('.')[0], 10) * 1000;
milliseconds = parseInt(parts[2].split('.')[1], 10);
totalMilliseconds += (hours + minutes + seconds + milliseconds);
}
if (!unit || unit.toLowerCase() == 'ms'){
return totalMilliseconds/times.length + ' milliseconds';
}
else if (unit.toLowerCase() == 's') {
return (totalMilliseconds/1000)/times.length + ' seconds';
}
}
}
// parameters:
// times: an array of times in your supplied format, 'HH:MM:SS:mm',
// unit: a string ('ms' or 's'), denoting whether to return milliseconds or seconds.
var average = averageTimes(times,'s');
console.log(average);​
JS Fiddle demo.
References:
for(){/*...*/} loop.
parseInt().
split().
toLowerCase().