Develop Reference

Date object doesn't exist after definition?

I'm trying to make a function that returns an array of dates in between two dates. This is my code:
Date.prototype.addDays = function(days)
{
var date = new Date(this.valueOf());
date.setDate(date.getDate() + days);
return date;
}
function getdaterange(startdate, enddate)
{
var s = new Date(startdate);
var e = new Date(enddate);
var datearray = [s];
var done = false;
while(!done)
{
var date = datearray.pop().addDays(1);
if (date == e)
{
datearray.push(date);
done = true;
}
}
}
getdaterange("2018-09-01", "2018-09-25");
The function isn't done yet, but when I try to manipulate the date object on the line that sets the variable "date", it comes back as undefined or says that .pop() isn't a method of Date. I've tried several different configurations. (Where I change how I am manipulating the date object. For example: defining the variable and then calling the .addDays() method afterwards.)
This is just one of them. Does anybody know whats going on?
Thanks for any help in advanced.
Thanks for your help from the comments. Edited Code:
Date.prototype.addDays = function(days)
{
var date = new Date(this.valueOf());
date.setDate(date.getDate() + days);
return date;
}
function getdaterange(startdate, enddate)
{
var s = new Date(startdate);
var e = new Date(enddate);
var datearray = [s];
var done = false;
while(!done)
{
var temp = datearray;
var date = temp.pop().addDays(1);
if (date.valueOf() == e.valueOf())
{
datearray.push(date);
done = true;
}
else
{
datearray.push(date);
}
}
return datearray;
}
console.log(getdaterange("2018-09-01", "2018-09-25"));

Rather than trying to 'extend' the Date class, you can encapsulate the desired logic in it's own class as follows
class DateUtil {
static addDays(date, days) {
return date.setDate(date.getDate() + days)
}
static getDateRange(dateStart, dateEnd) {
let date = new Date(dateStart);
let endDate = new Date(dateEnd);
let dates = [];
while (date < endDate) {
dates.push(new Date(this.addDays(date, 1)))
}
return dates;
}
}
DateUtil.getDateRange('2018-09-01', '2018-09-25')
.forEach(date => console.log(date.toString()));

What I ended up needing to do (after fixing the first problem) was set var temp equal to var datearray through a method like Array.from(). That way temp wasn't pointing to datearray directly and I always ended up with one item in the array.
Date.prototype.addDays = function(days)
{
var date = new Date(this.valueOf());
date.setDate(date.getDate() + days);
return date;
}
function getdaterange(startdate, enddate)
{
var s = new Date(startdate);
var e = new Date(enddate);
var datearray = [s];
var done = false;
while(!done)
{
var temp = Array.from(datearray);
var date = temp.pop().addDays(1);
if (date.valueOf() == e.valueOf())
{
datearray.push(date);
done = true;
}
else
{
datearray.push(date);
}
}
return datearray;
}

Generate date range given date from and to

I have an array of object:
[{from:'2017-05-02',to:'2017-05-12',event:'google map launch day'},
{from:'2017-05-03',to:'2017-05-14',event:'marie"s farewell'},
{from:'2017-05-20',to:'2017-05-20',event:'iphone showcase'}]
I want to map the event property to array of object below
[{
date: "2017-05-01"
},
{
date: "2017-05-02",
event: ['google map launch day']
},
{
date: "2017-05-03",
event: ['google map launch day', 'marie"s farewell']
},
{
date: "2017-05-04",
event: ['google map launch day', 'marie"s farewell']
}
..
]
https://pastebin.com/raw/Uv3U8zCy
I have no control over the first array of object, it came from an external API, I want to build a custom calendar, I'm struggling to map to a new format of array of object.
function generateDates(startDate, stopDate) {
var dateArray = [];
var currentDate = moment(startDate);
var stopDate = moment(stopDate);
while (currentDate <= stopDate) {
dateArray.push({ date: moment(currentDate).format('YYYY-MM-DD') });
currentDate = moment(currentDate).add(1, 'days');
}
return dateArray;
}
generateDates('2017-05-01', '2017-05-31');
I'm able to generate days of a month using momentjs but I'm still stuck.

You can use .isBetween of moment.js and get Events from iterating date as below.
var eventData = [{from:'2017-05-02',to:'2017-05-12',event:'google map launch day'},
{from:'2017-05-03',to:'2017-05-14',event:'marie"s farewell'},
{from:'2017-05-20',to:'2017-05-20',event:'iphone showcase'}]
// Get events for passed date
function getEvents(curDate){
return eventData.reduce(function(res,obj){
if(moment(curDate).isBetween(obj.from, obj.to, null, '[]'))
res.push(obj.event);
return res;
},[])
}
function generateDates(startDate, stopDate) {
var dateArray = [];
var dateArray = [];
var currentDate = moment(startDate);
var stopDate = moment(stopDate);
while (currentDate <= stopDate) {
dateArray.push({
date: moment(currentDate).format('YYYY-MM-DD'),
event:getEvents(currentDate) // Get events array here
});
currentDate = moment(currentDate).add(1, 'days');
}
return dateArray;
}

You could use a hash table as reference to the generated dates and iterate later in the same style the events.
function getRanges(data, startDate, stopDate) {
function generateDates(startDate, stopDate) {
var currentDate = moment(startDate),
stopDate = moment(stopDate),
date;
while (currentDate <= stopDate) {
date = moment(currentDate).format('YYYY-MM-DD');
hash[date] = { date: date };
dateArray.push(hash[date]);
currentDate = moment(currentDate).add(1, 'days');
}
}
var dateArray = [],
hash = {};
generateDates(startDate, stopDate);
data.forEach(function (a) {
var currentDate = moment(a.from),
stopDate = moment(a.to),
date;
while (currentDate <= stopDate) {
date = moment(currentDate).format('YYYY-MM-DD');
hash[date].event = hash[date].event || [];
hash[date].event.push(a.event);
currentDate = moment(currentDate).add(1, 'days');
}
});
return dateArray;
}
var data = [{ from: '2017-05-02', to: '2017-05-12', event: 'google map launch day' }, { from: '2017-05-03', to: '2017-05-14', event: 'marie"s farewell' }, { from: '2017-05-20', to: '2017-05-20', event: 'iphone showcase' }];
console.log(getRanges(data, '2017-05-01', '2017-05-31'));
.as-console-wrapper { max-height: 100% !important; top: 0; }
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.15.2/moment.min.js"></script>

How to return an array of all the dates between two selected dates using javascript

For my class assignment, I need to return an array of dates in between two selected dates on a calendar (arrival & departure).
I was given two sets of code that I can use, however I can't figure out how to link them together.
var arrival = document.getElementById('arrivalDate');
console.log(arrival.value);
var checkout = document.getElementById('departureDate');
console.log(checkout.value);
// Figure out the number of days they are check in for.
var days = checkout.value.split('-')[2] - arrival.value.split('-')[2];
console.log(days);
function dateRange(arrival, days) {
range = [];
// Starting At
return range;
}
// Returns an array of dates between the two dates
var getDates = function(startDate, endDate) {
var dates = [],
currentDate = startDate,
addDays = function(days) {
var date = new Date(this.valueOf());
date.setDate(date.getDate() + days);
return date;
};
while (currentDate <= endDate) {
dates.push(currentDate);
currentDate = addDays.call(currentDate, 1);
}
return dates;
};
// Usage
var dates = getDates(new Date(2013,10,22), new Date(2013,11,25));
dates.forEach(function(date) {
console.log(date);
});

Seems pretty simple when you've already been given the answer!
var arrivalDate = new Date(document.getElementById('arrivalDate').value);
var departureDate = new Date(document.getElementById('departureDate').value);
var dateRange = getDates(arrivalDate, departureDate);

Get a list of dates between two dates using javascript

From JavaScript is there a way to get list of days between two dates from MySQL format. I don't want to use any library for this.
This is what i did.
function generateDateList(from, to) {
var getDate = function(date) { //Mysql Format
var m = date.getMonth(), d = date.getDate();
return date.getFullYear() + '-' + (m < 10 ? '0' + m : m) + '-' + (d < 10 ? '0' + d : d);
}
var fs = from.split('-'), startDate = new Date(fs[0], fs[1], fs[2]), result = [getDate(startDate)], start = startDate.getTime(), ts, end;
if ( typeof to == 'undefined') {
end = new Date().getTime();
} else {
ts = to.split('-');
end = new Date(ts[0], ts[1], ts[2]).getTime();
}
while (start < end) {
start += 86400000;
startDate.setTime(start);
result.push(getDate(startDate));
}
return result;
}
console.log(generateDateList('2014-2-27', '2014-3-2'));
I test it from chrome and nodejs below are the result.
[ '2014-02-27',
'2014-02-28',
'2014-02-29',
'2014-02-30',
'2014-02-31',
'2014-03-01',
'2014-03-02' ]
yeh big leap year:-D..., how can i fix this? or is there any better way.?

const listDate = [];
const startDate ='2017-02-01';
const endDate = '2017-02-10';
const dateMove = new Date(startDate);
let strDate = startDate;
while (strDate < endDate) {
strDate = dateMove.toISOString().slice(0, 10);
listDate.push(strDate);
dateMove.setDate(dateMove.getDate() + 1);
};

Take the start date and increment it by one day until you reach the end date.
Note: MySQL dates are standard format, no need to parse it by hand just pass it to the Date constructor: new Date('2008-06-13').
const addDays = (date, days = 1) => {
const result = new Date(date);
result.setDate(result.getDate() + days);
return result;
};
const dateRange = (start, end, range = []) => {
if (start > end) return range;
const next = addDays(start, 1);
return dateRange(next, end, [...range, start]);
};
const range = dateRange(new Date("2014-02-27"), new Date("2014-03-02"));
console.log(range);
console.log(range.map(date => date.toISOString().slice(0, 10)))
Here I use a recursive function, but you could achieve the same thing using a while (see other answers).

I have used this one from
https://flaviocopes.com/how-to-get-days-between-dates-javascript/
const getDatesBetweenDates = (startDate, endDate) => {
let dates = []
//to avoid modifying the original date
const theDate = new Date(startDate)
while (theDate < new Date(endDate)) {
dates = [...dates, new Date(theDate)]
theDate.setDate(theDate.getDate() + 1)
}
dates = [...dates, new Date(endDate)]
return dates
}
Invoke the function as follows:
getDatesBetweenDates("2021-12-28", "2021-03-01")
Note - I just had to fix issues with the Date object creation (new Date()) in the while loop and in the dates array. Other than that the code is pretty much same as seen on the above link

dateRange(startDate, endDate) {
var start = startDate.split('-');
var end = endDate.split('-');
var startYear = parseInt(start[0]);
var endYear = parseInt(end[0]);
var dates = [];
for(var i = startYear; i <= endYear; i++) {
var endMonth = i != endYear ? 11 : parseInt(end[1]) - 1;
var startMon = i === startYear ? parseInt(start[1])-1 : 0;
for(var j = startMon; j <= endMonth; j = j > 12 ? j % 12 || 11 : j+1) {
var month = j+1;
var displayMonth = month < 10 ? '0'+month : month;
dates.push([i, displayMonth, '01'].join('-'));
}
}
return dates;
}

var oDate1 = oEvent.getParameter("from"),
oDate2 = oEvent.getParameter("to");
var aDates = [];
var currentDate = oDate1;
while (currentDate <= oDate2) {
aDates.push(new Date(currentDate));
currentDate.setDate(currentDate.getDate() + 1);
}

I expanded Công Thắng's great answer to return {years, months, days}, thought it was worth sharing:
function getDates(startDate, endDate) {
const days = [],
months = new Set(),
years = new Set()
const dateMove = new Date(startDate)
let date = startDate
while (date < endDate){
date = dateMove.toISOString().slice(0,10)
months.add(date.slice(0, 7))
years.add(date.slice(0, 4))
days.push(date)
dateMove.setDate(dateMove.getDate()+1) // increment day
}
return {years: [...years], months: [...months], days} // return arrays
}
console.log(getDates('2016-02-28', '2016-03-01')) // leap year
/* =>
{
years: [ '2016' ],
months: [ '2016-02', '2016-03' ],
days: [ '2016-02-28', '2016-02-29', '2016-03-01' ]
}
*/
const {months} = getDates('2016-02-28', '2016-03-01') // get only months
Basically the function just increments the built-in Date object by one day from start to end, while the Sets capture unique months and years.

javascript check end date is greater than or equal to start date

Is it possible to check whether an end date is greater than or equal to a start date in Javascript? My dates are strings in the format 'dd/mm/yyyy'.

try this
var startDate = "05/01/2011";
var endDate = "09/01/2011";
var regExp = /(\d{1,2})\/(\d{1,2})\/(\d{2,4})/;
if(parseInt(endDate.replace(regExp, "$3$2$1")) > parseInt(startDate.replace(regExp, "$3$2$1"))){
alert("greater");
}

If the string format ('dd/mm/yyyy') doesn't change, this function should work:
function endAfterStart(start,end){
return new Date(start.split('/').reverse().join('/')) <
new Date(end.split('/').reverse().join('/'));
}
alert(endAfterStart('05/01/2011','09/01/2011')); //=> true
Or extend the Date.prototype:
Date.prototype.isBefore = Date.prototype.isBefore || function(dat){
return this < dat;
}
new Date('05/01/2011'.split('/').reverse().join('/'))
.before( new Date('09/01/2011'.split('/').reverse().join('/')) ); //=>true

Most simple way to do this.
function endAfterStart(start, end) {
var startDate = new Date(start);
var endDate = new Date(end);
return endDate.getTime() >= startDate.getTime();
}

function isDate(value)
{
var fromDate = document.getElementById("fromDate").value
var toDate= document.getElementById("toDate").value
//var curr_Date= new SimpleDateFormat("dd/mm/yyyy");
var dateRegEx = null;
dateRegEx = new RegExp(/^(((0[1-9]|[12]\d|3[01])\/(0[13578]|1[02])\/((19|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|30)\/(0[13456789]|1[012])\/((19|[2-9]\d)\d{2}))|((0[1-9]|1\d|2[0-8])\/02\/((19|[2-9]\d)\d{2}))|(29\/02\/((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))))$/g);
if (dateRegEx.test(fromDate)){
}
else{
alert("Invalid from date");
return false;
}
dateRegEx = new RegExp(/^(((0[1-9]|[12]\d|3[01])\/(0[13578]|1[02])\/((19|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|30)\/(0[13456789]|1[012])\/((19|[2-9]\d)\d{2}))|((0[1-9]|1\d|2[0-8])\/02\/((19|[2-9]\d)\d{2}))|(29\/02\/((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))))$/g);
if(dateRegEx.test(toDate)) {
}
else{
alert("Invalid to date");
return false;
}
var stDate = new Date(fromDate);
var enDate = new Date(toDate);
var compDate = enDate - stDate;
//var fdate=enDate-curr_Date;
if(compDate >= 0)
return true;
else
{
alert("To Date cannot be smaller than From Date");
return false;
}
/**/
}
This will work for Leap years also..in dd/mm/yyyy format(not any other format).

Took me some time to find, but JQuery implements this exact functionality with DatePicker date-range. (Source code available in link as well.)
Moment.js also handles date comparisons very well using the diff function.

check out this function
function CompareDates()
{
var str1 = document.getElementById("Fromdate").value;
var str2 = document.getElementById("Todate").value;
var dt1 = parseInt(str1.substring(0,2),10);
var mon1 = parseInt(str1.substring(3,5),10);
var yr1 = parseInt(str1.substring(6,10),10);
var dt2 = parseInt(str2.substring(0,2),10);
var mon2 = parseInt(str2.substring(3,5),10);
var yr2 = parseInt(str2.substring(6,10),10);
var date1 = new Date(yr1, mon1, dt1);
var date2 = new Date(yr2, mon2, dt2);
if(date2 < date1)
{
alert("To date cannot be greater than from date");
return false;
}
else
{
alert("Submitting ...");
document.form1.submit();
}
}

Try this,
function isDateCompare(){
var leadDate = document.getElementById('strDate').value;
var closeDate = document.getElementById('strDateClosed').value;
var date1 = new Date();
date1.setFullYear(leadDate.substr(6,4),(leadDate.substr(3,2)-1),leadDate.substr(0,2));
var date2 = new Date();
date2.setFullYear(closeDate.substr(6,4),(closeDate.substr(3,2)-1),closeDate.substr(0,2));
if (date1> date2)
{
alert("Expected Closed date cannot be less than Lead date.");
return false;
}
else
{
alert("true");
return false;
}
}

First use this function will convert string to Date type in js:
function common_getDateFromUI(str) {
var arr = str.split("/");
var returnDate = new Date(arr[2], arr[1] - 1, arr[0], 0, 0, 0, 0);
return returnDate;
}
Second: after you get the javascript date type, you just compare it as normal type like date1 > date2 or date1 == date2.
Or use this function to get the difference date between date:
function CalendarDays(startDate, endDate) {
if (endDate < startDate)
return 0;
// Calculate days between dates
var millisecondsPerDay = 86400 * 1000; // Day in milliseconds
startDate.setHours(0, 0, 0, 1); // Start just after midnight
endDate.setHours(23, 59, 59, 999); // End just before midnight
var diff = endDate - startDate; // Milliseconds between datetime objects
var days = Math.round(diff / millisecondsPerDay);
return days;
}
Follow this link is a simple demo to get difference days between dates. Link demo here

if (iForm.DiddfromDate.value == "")
{
alert(" Please enter a value");
iForm.DiddfromDate.focus();
return false;
}
if (iForm.DiddtoDate.value == "")
{
alert(" Please enter a value");
iForm.DiddtoDate.focus();
return false;
}
try {
var d1 = iForm.DiddfromDate.value.substr(0, 2);
var m1 = iForm.DiddfromDate.value.substr(3, 2);
var y1 = iForm.DiddfromDate.value.substr(6, 4);
var StrDate = m1 + "/" + d1 + "/" + y1;
var d2 = iForm.DiddtoDate.value.substr(0, 2);
var m2 = iForm.DiddtoDate.value.substr(3, 2);
var y2 = iForm.DiddtoDate.value.substr(6, 4);
var EndDate = m2 + "/" + d2 + "/" + y2;
var startDate = new Date(StrDate);
var endDate = new Date(EndDate);
if (startDate > endDate) {
alert('To date should be greater than From date.');
iForm.DiddfromDate.value = '';
iForm.DiddtoDate.value = '';
iForm.DiddfromDate.focus();
return false;
}
} catch (e) { alert(e.Description); }
return true;

Just convert the string to date and use getTime method of Date object to compare it.
Example code
var startDate = '04/04/2015'; //date in dd/mm/yyyy format
var endDate = '05/04/2015';
function compareDates(sDate, eDate) {
var dateTime1 = new Date(sDate).getTime(),
dateTime2 = new Date(eDate).getTime();
var diff = dateTime2 - dateTime1;
if (diff > 0) {
alert("endDate is greater than startDate");
return true;
}
}
compareDates(startDate, endDate);
Working Fiddle