javascript - round up/ round down a momentjs moment to nearest minute

Question

How do you round up/ round down a momentjs moment to nearest minute?

I have checked the docs, but there doesn't appear to be a method for this.

Note that I do not want a string rounded to the nearest minute, I want a moment returned (or modified in place, either is fine). I prefer not to have to convert to a string, and the convert back too.

Thanks.

---

As requested, here is some code:

var now = new moment(new Date());

if (now.seconds() > 0) {
    now.add('minutes', -1);
}

now.seconds(0);

as you can see, I have managed to manually round down the moment here, but it seems rather hacky. Just after a more elegant way of accomplishing this.

Answer 1

To round up, you need to add a minute and then round it down. To round down, just use the startOf method.

Note the use of a ternary operator to check if the time should be rounded (for instance, 13:00:00 on the dot doesn't need to be rounded).

Round up/down to the nearest minute

var m = moment('2017-02-17 12:01:01');
var roundDown = m.startOf('minute');
console.log(roundDown.toString()); // outputs Tue Feb 17 2017 12:01:00 GMT+0000

var m = moment('2017-02-17 12:01:01');
var roundUp = m.second() || m.millisecond() ? m.add(1, 'minute').startOf('minute') : m.startOf('minute');
console.log(roundUp.toString());  // outputs Tue Feb 17 2017 12:02:00 GMT+0000

Round up/down to the nearest hour

var m = moment('2017-02-17 12:59:59');
var roundDown = m.startOf('hour');
console.log(roundDown.toString()); // outputs Tue Feb 17 2017 12:00:00 GMT+0000

var m = moment('2017-02-17 12:59:59');
var roundUp = m.minute() || m.second() || m.millisecond() ? m.add(1, 'hour').startOf('hour') : m.startOf('hour');
console.log(roundUp.toString());  // outputs Tue Feb 17 2017 13:00:00 GMT+0000