Javascript loop between date ranges

Question

Given two Date() objects, where one is less than the other, how do I loop every day between the dates?

for(loopDate = startDate; loopDate < endDate; loopDate += 1)
{

}

Would this sort of loop work? But how can I add one day to the loop counter?

Thanks!

Answer 1

var start = new Date("2014-05-01"); //yyyy-mm-dd
var end = new Date("2014-05-05"); //yyyy-mm-dd

while(start <= end){

    var mm = ((start.getMonth()+1)>=10)?(start.getMonth()+1):'0'+(start.getMonth()+1);
    var dd = ((start.getDate())>=10)? (start.getDate()) : '0' + (start.getDate());
    var yyyy = start.getFullYear();
    var date = dd+"/"+mm+"/"+yyyy; //yyyy-mm-dd

    alert(date); 

    start = new Date(start.setDate(start.getDate() + 1)); //date increase by 1
}

Answer 2

Let us assume you got the start date and end date from the UI and stored it in the scope variable in the controller.

Then declare an array which will get reset on every function call so that on the next call for the function the new data can be stored.

var dayLabel = [];

Remember to use new Date(your starting variable) because if you dont use the new date and directly assign it to variable the setDate function will change the origional variable value in each iteration`

for (var d = new Date($scope.startDate); d <= $scope.endDate; d.setDate(d.getDate() + 1)) {
                dayLabel.push(new Date(d));
            }

Answer 3

If startDate and endDate are indeed date objects you could convert them to number of milliseconds since midnight Jan 1, 1970, like this:

var startTime = startDate.getTime(), endTime = endDate.getTime();

Then you could loop from one to another incrementing loopTime by 86400000 (1000*60*60*24) - number of milliseconds in one day:

for(loopTime = startTime; loopTime < endTime; loopTime += 86400000)
{
    var loopDay=new Date(loopTime)
    //use loopDay as you wish
}

Answer 4

I think I found an even simpler answer, if you allow yourself to use Moment.js:

// cycle through last five days, today included
// you could also cycle through any dates you want, mostly for
// making this snippet not time aware
const currentMoment = moment().subtract(4, 'days');
const endMoment = moment().add(1, 'days');
while (currentMoment.isBefore(endMoment, 'day')) {
  console.log(`Loop at ${currentMoment.format('YYYY-MM-DD')}`);
  currentMoment.add(1, 'days');
}

<script src="https://cdn.jsdelivr.net/npm/moment@2/moment.min.js"></script>

Answer 5

If you want an efficient way with milliseconds:

var daysOfYear = [];
for (var d = begin; d <= end; d = d + 86400000) {
    daysOfYear.push(new Date(d));
}

Answer 6

Based on Tabare's Answer, I had to add one more day at the end, since the cycle is cut before

var start = new Date("02/05/2013");
var end = new Date("02/10/2013");
var newend = end.setDate(end.getDate()+1);
var end = new Date(newend);
while(start < end){
   alert(start);           

   var newDate = start.setDate(start.getDate() + 1);
   start = new Date(newDate);
}