CODEWITHSUNDEEP
javascript
Bas
Bas

Reputation: 2210

Getting the amount of minutes when calculating the seconds between 2 dates

I have this piece of code in javascript to calculate the amount of seconds between 2 dates:

function dateDiffInSeconds(a, b) {
    var utc1 = Date.UTC(a.getFullYear(), a.getMonth(), a.getDate(), a.getHours(), a.getMinutes(), a.getSeconds());
    var utc2 = Date.UTC(b.getFullYear(), b.getMonth(), b.getDate(), b.getHours(), b.getMinutes(), b.getSeconds());

    return Math.floor((utc2 - utc1) / 1000);
}

I have made this little setIntervalfunction to make it update every second and show the number on the screen:

var j = new Date('July, 05, 2012');
setInterval(function () {
    var n = new Date();
    document.getElementById("a").innerHTML = dateDiffInSeconds(j, n);
}, 1000);

This works great and there's no problem with that.

Now i have tried with the same piece of code to calculate every minute in that seconds, so i thought:

On every 60 seconds, count up the minutes variable by 1;

So i made it to this:

var j = new Date('July, 05, 2012');
var minutes = 0;
setInterval(function () {
    var n = new Date();
    document.getElementById("a").innerHTML = dateDiffInSeconds(j, n);
    if(dateDiffInSeconds(j, n) > 60) {
        minutes++;
        console.log(mins);
    }
}, 1000);

Problem

When i run this the minutes variable is counting up, but only on every count by 1, and not by each 60 seconds.

Wanted result

How do i make it so that on each 60 seconds calculated with the dateDiffInSeconds function , its counting up the minutes variable by 1?

Demo here (check console)

Upvotes: 0

Views: 75

Answers (3)

Matt Wolfe
Matt Wolfe

Reputation: 9294

Here check out this answer:

http://jsfiddle.net/Y5mew/4/

Minutes: <span id="minutes"></span>

Seconds: <span id="seconds"></span>



function dateDiffInSeconds(a, b) {
    var utc1 = Date.UTC(a.getFullYear(), a.getMonth(), a.getDate(), a.getHours(), a.getMinutes(), a.getSeconds());
    var utc2 = Date.UTC(b.getFullYear(), b.getMonth(), b.getDate(), b.getHours(), b.getMinutes(), b.getSeconds());

    return Math.floor((utc2 - utc1) / (1000));
}

var j = new Date();
var mins = 0;
document.getElementById("minutes").innerHTML = mins;
setInterval(function () {
    var n = new Date();
    document.getElementById("seconds").innerHTML = dateDiffInSeconds(j, n);

    if(dateDiffInSeconds(j, n) > 60) {
        mins++;
        document.getElementById("minutes").innerHTML = mins;
        j = new Date();
    }
}, 1000)

;

Upvotes: 0

Strille
Strille

Reputation: 5781

You don't really need to "count up" the minutes variable, you can calculate it using the diff in seconds. If you want to detect when the number of minutes increases, you can just compare the newly calculated minutes with the value you calculated last time, and if they differ you can take action:

function dateDiffInSeconds(a, b) {
    return Math.floor((b.getTime() - a.getTime()) / 1000);
}

var j = new Date('July, 05, 2012');
var oldDiffInMinutes = null;

setInterval(function () {
    var n = new Date();
    var diffInSeconds = dateDiffInSeconds(j, n);
    var diffInMinutes = Math.floor(diffInSeconds/60);

    document.getElementById("a").innerHTML = diffInSeconds;

    if (diffInMinutes !== oldDiffInMinutes) {
        console.log("Minutes changed: " + diffInMinutes);
        oldDiffInMinutes = diffInMinutes;
    }
}, 1000);

http://jsfiddle.net/Y5mew/3/

Upvotes: 1

durbnpoisn
durbnpoisn

Reputation: 4669

You need to use a secondary counter inside your loop...

Psuedo code for your loop:

secs = 1000
minutes = 0
minuteCounter = 0

for (xx=0;xx<secs;xx++){
minuteCounter++
if (minuteCounter==60){
//We've reached one minute
minutes++
minuteCounter=0
}
}

This will count up the minutes by adding one every time the counter reaches 60.

Upvotes: 1

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