Moment: How to compare only HH:mm?

[artjomzab]

I am using moment.js with my node.js project

isWithinTime: function(end) {

     var moment = require('moment');
     var now = moment(new Date()).format('HH:mm');
     var end = moment(new Date(end)).format('HH:mm');

     if (now.toString() > end.toString()) {
         return false;
     }
     return true;
}

I want to compare only time in HH:mm format. However it does not work because

'7:00' > '2:00'

returns false. Any ideas how to compare HH:mm?

[icambron]

Usually, if you don't care about the end time's date, it's better to just keep track of the hours and minutes explicitly, but of course I don't know anything about your app. So to answer it directly, define a new function for returning the number of minutes:

var minutesOfDay = function(m){
  return m.minutes() + m.hours() * 60;
}

and then check that:

return minutesOfDay(now) > minutesOfDay(end);

As an aside, moment() does the same thing as moment(new Date()), so that should save you some text.

[rfossella]

After looking through other MomentJS questions I'm still stumped as to how one would use moment to simply compare two different times

I need (want) the day/date to be ignored.

Use case:
I'm reading a schedule w/ start & end times from a config file. This is done using Node.js

Start time = 6:30 PM
End time = 3:30 AM

var currentTime= moment();    // e.g. 11:00 pm
var startTime = moment('06:30 pm', "HH:mm a");
var endTime = moment('03:30 am', "HH:mm a");

amIBetween = currentTime.isBetween(startTime , endTime);
console.log(amIBetween);   //  returns false.  if date ignored I expect TRUE

My scenario is technically spanning two days and I understand why it's false.

I need (expect) moment to return TRUE - i.e. that currentTime isBeteen startTime and endTime and falls in that range.

I thought I had it solved by checking if endTime hour is > 12 then add a day to make moment understand it's the following day. e.g.

if (startTime.hour() >=12 && endTime.hour() <=12 )
    {
        endTime.add(1, "days");       // handle spanning days
    }

    var isBetween = currentTime.isBetween(startTime, endTime);   // TRUE

But if currentTime is also after midnight then it breaks - e.g.

01:30am will not be considered between 06:30pm and 03:30am - also because of different days

Any other suggestions for accomplishing this and simply ignoring the day/date?

I'm finding it hard to believe that it's this complex, but maybe it is :

Here's further clarification that issue arises with spanning days, even when trying to be more explicit:

var currentTime= moment('11:00p', "HH:mm a");
var startTime = moment('06:00p', "HH:mm a");
var endTime = moment('03:30a', "HH:mm a");

currentTime.toString(); //"Fri Oct 28 2016 23:00:00 GMT-0400"
startTime.toString();   // "Fri Oct 28 2016 18:00:00 GMT-0400"
endTime.toString();    // "Fri Oct 28 2016 03:30:00 GMT-0400"

currentTime.isBetween(startTime, endTime);  // false
currentTime.isAfter(endTime) && currentTime.isBefore(startTime); //false
currentTime.isAfter(startTime) && currentTime.isBefore(endTime); //false

Seems kind of obvious that they'd be false since the _day/date_ is considered by moment. This is what I'm trying to get around.

The following would work:

endTime.add(1, "days");
currentTime.isBetween(startTime, endTime);  // TRUE

This would mean however, that I'd need to check if the START TIME was before 12AM && the ENDTIME as after 12AM then add 1 day to ENDTIME.

[icambron]

I guess I don't quite understand what you mean by "ignoring the day". If you're comparing these two times

var startTime = moment('06:00p', "HH:mm a");
var endTime = moment('03:30a', "HH:mm a");

somehow the system has to know that you mean 3:30 _tomorrow_. I mean, how could it ever work? Surely, you don't think that in the absence of day information that 3:30 AM is after 6:00 PM...The problem is that you have some extra context that Moment doesn't have, which is that the endTime is expected to be after the startTime; that's obvious from your variable names, but Moment doesn't and can't know that. You'll have to tell it.

So how about this:

if (startTime.isAfter(endTime)){
  endTime.add(1, 'days');
}

[rfossella]

Yeah, I understand the confusion. Without knowing that we mean "3:30am" is the next day it is tricky.

Disregarding the day/date:
_If I ask, "is 11pm between 9pm and 3am" I expect the answer to be true.
If I ask, "is 11pm between 3am and 9pm" I expect the answer to be false._

Since I can't simply ignore the date using moment I started checking for ALL times before/after 12 and ended up with:

if ( (startTime.hour() >=12 && endTime.hour() <=12 ) || endTime.isBefore(startTime) )
    {
        endTime.add(1, "days");       // handle spanning days endTime

        if (currentTime.hour() <=12 )
        {
            currentTime.add(1, "days");       // handle spanning days currentTime
        }
    }

The fiddle I have here displays my use case scenarios. Hope it's useful.
https://jsfiddle.net/rfossella/66wjtnvk/1/

Thanks again for your time (no pun intended :-) )

[StefanRein]

Or just something like this function:

Updated after @Machibuse answer

function getTime(dateTime: Moment): Moment {
    return moment({h: dateTime.hours(), m: dateTime.minutes()});
}

/** USAGE EXAMPLE */
const first: Moment = getTime( moment([2018, 5, 1, 17, 0, 0]) ); // 17:00
const second: Moment = getTime( moment([2013, 8, 2, 18, 0, 0]) );  // 18:00
const third: Moment = getTime( moment([2015, 3, 3, 19, 0, 0]) );  // 19:00

second.isAfter(first, 'minutes'); // true
first.isBefore(second, 'minutes'); // true
first.isAfter(second, 'minutes'); // false
second.isBefore(first, 'minutes'); // false

second.isBetween(first, third, 'minutes', '[]'); // true 
third.isBetween(first, second, 'minutes', '[]'); // false

// second.diff(first, 'minutes') => 60
// second.diff(third, 'minutes') => -60
// third.diff(first, 'minutes') => 120

So you could the is the MomentJS methods isBetween, isAfter, isBefore only with the time and not the date.

[Machibuse]

Try

second.isBetween(third, first, 'minutes', '[]'); // true

Its not a bug in Moment, ist a missing information in the documentation that the first parameter must be the earlier date.

[rsmets]

Still pretty stumped by this one too. I have spent more on it than I care to admit! @Machibuse or @rfossella what implementation ended up working?

[kdavong]

I used to be stucked with same issue, and finally found a way to make it works 👍 formatting time in military time, I hope it might help...

const isTimeBetween = function(startTime, endTime, serverTime) {
    let start = moment(startTime, "H:mm")
    let end = moment(endTime, "H:mm")
    let server = moment(serverTime, "H:mm")
    if (end < start) {
        return server >= start && server<= moment('23:59:59', "h:mm:ss") || server>= moment('0:00:00', "h:mm:ss") && server < end;
    }
    return server>= start && server< end
}

Then I can use this function like so:

isTimeBetween('22:30', '3:00', '23:50') //return true
isTimeBetween('22:30', '3:00', '1:50') //return true
isTimeBetween('22:30', '3:00', '4:50') //return false

[googlicius]

@kdavong It's works very well, thank you!

[rfossella]

Hi,
I rechecked the fiddle I posted years ago and it is still active and still works. FYI: My example does not introduce military time, in case you do need that.

The fiddle I have here displays my use case scenarios. Hope it's useful.
https://jsfiddle.net/rfossella/66wjtnvk/1/

Rob