Find available days within a date range - javascript

Let's say there's a system that shows date availability for events. We have a main date range where all events go. Events can be date ranges themselves too.
Example:
[Date X]========================================[Date Y]
[A]=====[A] [B]=====[B][C]=====[C]
[ Event A ][ Open ][ Event B ][ Event C ]
Where Date X and Date Y are the main date range where events go. And A,B, and C are events that have been scheduled.
How can I efficiently retrieve the open date range?
Example 2:
var rangeStart = new Date("04-01-2016");
var rangeEnd = new Date("04-31-2016");
var eventAStart = new Date("04-01-2016");
var eventAEnd = new Date("04-06-2016");
var eventBStart = new Date("04-15-2016");
var eventBEnd = new Date("04-30-2016");
I need to return something like:
var availableRangeStart = "04-07-2015";
var availableRangeEnd = "04-14-2016";
because these are the dates in the main range that are not overlapped by "event" ranges.
To be exact on what I am trying to do:
My app is a trip planner where the user sets the dates for their trip and then adds different destinations to that trip that have their own dates. (User is going on a trip to Europe April 1st to April 30th, they will be in Paris on April 1st to April 6, then they will be in London April 15th to April 30th). But the user has not planned anything from April 7th to April 14th. I am trying to return these dates so that when they add a new destination, the dates are pre-filled.

I just give you an algorithm because the final implementation depends of your code.
var aprilAvailableDays = [true, true, true, etc...] // a boolean for each day
aprilEvents.forEach(function (event) {
for (var i = event.startDay; i <= event.endDay; i++) {
aprilAvailableDays[i] = false;
}
});

Here is a solution that returns from/to periods that are free:
// Helper function
function addDays(date, days) {
return new Date(date.getTime() + days * 24*60*60*1000);
}
// Main function
function gaps(period, events) {
events = events.slice(0).filter(function (a) {
// Exclude events which are outside the main period
return a.to >= period.from && a.from <= period.to;
}).sort(function (a, b) {
// Sort events by their starting date
return a.from - b.from;
});
var result = events.reduce(function (result, curr) {
if (curr.from - result.free > 0) {
// gap found
result.gaps.push({
from: result.free,
to: addDays(curr.from, -1)
});
}
if (curr.to - result.free >= 0) {
// first free day is after this event
result.free = addDays(curr.to, 1)
}
return result;
}, { gaps: [], free: period.from } );
// Potentially add gap between last event end period-end
if (period.to - result.free >= 0) {
result.gaps.push({
from: result.free,
to: period.to
});
}
return result.gaps;
}
// Sample data:
var period = {
from: new Date('2016-01-01'),
to: new Date('2016-12-31')
};
var events = [
{ from: new Date('2016-02-01'), to: new Date('2016-02-29') },
{ from: new Date('2016-03-01'), to: new Date('2016-03-15') },
{ from: new Date('2016-04-16'), to: new Date('2016-04-30') },
];
// Call to function
var res = gaps(period, events);
// Output in snippet
document.write('<pre>' + JSON.stringify(res, null, 4));

Related

To sort array based on startdtate and present job or no

I am making a dynamic portfolio for myself using VueJS.
I created a way to update experiences and order it based on currently ongoing jobs showing first sorted in ascending order meaning a job with start date May 2021 will show first and then March 2021 (both being present).
Next, if I set an end date for the job, it should update and place the current jobs in the front which isn't happening.
Algorithm:
newExp() {
this.editableExperience.sort((a,b) => {
a = a.period.split(' - ');
b = b.period.split(' - ');
let aStartDate = a[0];
let aEndDate = a[1];
let bStartDate = b[0];
let bEndDate = b[1];
if (aEndDate == 'Present' && bEndDate == 'Present') {
return new Date(bStartDate) - new Date(aStartDate);
} else if (aEndDate == 'Present') {
return a;
} else if (bEndDate == 'Present') {
return b;
} else {
return new Date(bStartDate) - new Date(aStartDate);
}
})
this.experience = this.editableExperience;
}
editableExperience is an array of experiences: (I have added only required information)
editableExperience = [{period: 'May 2021 - Present'}, {period: 'November 2020 - Present'}, {period: 'January 2021 - March 2021'}, {period: 'March 2018 - July 2020'}]
Exact issue situation:
Setting the third element to present job brings it to position 2 but giving it an end date again does not send it to position 3 again.
Setting the last element to present does not bring it in front of the non-present jobs.
Your compare function is returning a string or a number while the compare function should return either 1, 0 or -1 as per the MDN docs.
I have made changes to your code below:
newExp() {
this.editableExperience.sort((a,b) => {
a = a.period.split(' - ');
b = b.period.split(' - ');
let aStartDate = a[0];
let aEndDate = a[1];
let bStartDate = b[0];
let bEndDate = b[1];
if (aEndDate == 'Present' && bEndDate == 'Present') {
return (new Date(bStartDate) - new Date(aStartDate)) > 1 ? 1 : -1;
} else if (aEndDate == 'Present') {
return -1;
} else if (bEndDate == 'Present') {
return 1;
} else {
return (new Date(bStartDate) - new Date(aStartDate)) > 1 ? 1 : -1;
}
});
this.experience = this.editableExperience;
}
The view model is a little bit mixed with data model, I would suggest to keep a clean data model which hold the original values, it is good for processing like sort. then a a computed property as view model which is depend on the data model.
data: () => ({
editableExperience: [
{start: 202105, end: 999999},
{start: 202011, end: 999999},
{start: 202101, end: 202103},
{start: 201803, end: 202107},
],
}),
then the sorting will looks like:
this.editableExperience.sort((a,b) => {
return b['end'] === a['end']? b['start'] - a['start'] : b['end'] - a['end']
})
for your view(display)
computed: {
viewExperiences() {
const ve = []
for(const e of this.editableExperience) {
ve.push(this.getExperienceDisplay(e))
}
return ve
}
},
methods: {
formatExperienceDate(dateInt) {
if(dateInt === 999999) return 'Present'
const dateStr = dateInt.toString()
const date = new Date(dateStr.substring(0, 4) + '-' + dateStr.substring(4, 6))
return date.toLocaleDateString("en-US", {year: 'numeric', month: 'long'})
},
getExperienceDisplay(exp) {
const startDate = this.formatExperienceDate(exp['start'])
const endDate = this.formatExperienceDate(exp['end'])
return `${startDate} - ${endDate}`
},
}

How do I get the current school hour and time remaining?

I have this function:
function getInfoSchoolTime() {
var date = new Date();
var schoolBellTime = ["8:10","9:02","9:54","9:59","10:51","11:43","11:58","12:48","13:35","13:40","14:10","15:02","15:54"];
var remainingTime, currentHour;
for (var i = 0; i < schoolBellTime.length-1; i++) {
var startTime = schoolBellTime[i].split(":");
var endTime = schoolBellTime[i+1].split(":");
if (parseInt(startTime[0]) >= date.getHours() && parseInt(startTime[1]) >= date.getMinutes())
if (parseInt(endTime[0]) <= date.getHours() && parseInt(endTime[1]) <= date.getMinutes()) {
currentHour = i;
remainingTime=(parseInt(endTime[1])-date.getMinutes()+60)%60;
break;
}
}
if (currentHour == undefined)
return {current: -1, remaining: "not available"};
return {current: currentHour, remaining: remainingTime};
}
var info = getInfoSchoolTime();
console.log(info.current, info.remaining);
I have the schoolBellTime array that contains the timestamps of my school bell (I know, my school has strange bell times, these timestamps includes playtimes and lunchtime), this function is meant to return the 1st hour/2nd hour/3rd hour ... and the minutes that remains to the next hour/breaktime.
I checked all the code and can't find the error, it keeps returning {current: -1, remaining: "not available"}
The function at the top: setDateTime() takes a date and a time, and constructs a date object for that time.
Then I updated your function, I convert start and end to times on the current day, and then check if date.getTime() occurs between them. Then I simply subtract date.getTime() from end, and convert the result to minutes from milliseconds.
var setDateTime = function(date, str) {
var sp = str.split(':');
date.setHours(parseInt(sp[0], 10));
date.setMinutes(parseInt(sp[1], 10));
return date;
}
function getInfoSchoolTime() {
var date = new Date();
var schoolBellTime = ["8:10", "9:02", "9:54", "9:59", "10:51", "11:43", "11:58", "12:48", "13:35", "13:40", "14:10", "14:10", "15:02", "15:54"];
var remainingTime, currentHour, currentPeriod;
for (var i = 0; i < schoolBellTime.length - 1; i++) {
start = setDateTime(new Date(), schoolBellTime[i])
end = setDateTime(new Date(), schoolBellTime[i + 1])
if (date.getTime() > start.getTime() && date.getTime() < end.getTime()) {
currentHour = i
remainingTime = end.getTime() - date.getTime()
currentPeriod = ([schoolBellTime[i], schoolBellTime[i+1]]).join('-')
}
}
return {current: currentHour, currentPeriod: currentPeriod, remaining: Math.round(remainingTime * 0.0000166667)}
}
console.log(getInfoSchoolTime())
Here's a somewhat different approach, both to the code and the API. It uses two helper functions. Each should be obvious with a single example: pad(7) //=> "07" and pairs(['foo', 'bar', 'baz', 'qux']) //=> [['foo', 'bar'], ['bar', 'baz'], ['baz', 'qux']].
The main function takes a list of bell times and returns a function which itself accepts a date object and returns the sort of output you're looking for (period, remaining time in period.) This API makes it much easier to test.
const pad = nbr => ('00' + nbr).slice(-2)
const pairs = vals => vals.reduce((res, val, idx) => idx < 1 ? res : res.concat([[vals[idx - 1], val]]), [])
const schoolPeriods = (schoolBellTime) => {
const subtractTimes = (t1, t2) => 60 * t1.hour + t1.minute - (60 * t2.hour + t2.minute)
const periods = pairs(schoolBellTime.map(time => ({hour: time.split(':')[0], minute: +time.split(':')[1]})))
return date => {
const current = {hour: date.getHours(), minute: date.getMinutes()}
if (subtractTimes(current, periods[0][0]) < 0) {
return {message: 'before school day'}
}
if (subtractTimes(current, periods[periods.length - 1][1]) > 0) {
return {message: 'after school day'}
}
const idx = periods.findIndex(period => subtractTimes(current, period[0]) >= 0 && subtractTimes(period[1], current) > 0)
const period = periods[idx]
return {
current: idx + 1,
currentPeriod: `${period[0].hour}:${pad(period[0].minute)} - ${period[1].hour}:${pad(period[1].minute)}`,
remaining: subtractTimes(period[1], current)
}
}
}
const getPeriod = schoolPeriods(["8:10","9:02","9:54","9:59","10:51","11:43","11:58","12:48","13:35","13:40","14:10","14:10","15:02","15:54"])
console.log("Using current time")
console.log(getPeriod(new Date()))
console.log("Using a fixed time")
console.log(getPeriod(new Date(2017, 11, 22, 14, 27))) // will Christmas break ever come?!
I made a random guess at the behavior you would want if the date is outside the period range.
Internally, it creates a list of period objects that look like
[{hour:9, minute: 59}, {hour: 10, minute: 51}]
Perhaps it would be cleaner if instead of a two-element array it was an object with start and end properties. That would be an easy change.
Do note that for this to make sense, the bells need to be listed in order. We could fix this with a sort call, but I don't see a good reason to do so.
Here is an ES6 example using deconstruct (const [a,b]=[1,2]), array map, array reduce, partial application (closure) and fat arrow function syntax.
This may not work in older browsers.
//pass date and bellTimes to function so you can test it more easily
// you can partially apply bellTimes
const getInfoSchoolTime = bellTimes => {
//convert hour and minute to a number
const convertedBellTimes = bellTimes
.map(bellTime=>bellTime.split(":"))//split hour and minute
.map(([hour,minute])=>[new Number(hour),new Number(minute)])//convert to number
.map(([hour,minute])=>(hour*60)+minute)//create single number (hour*60)+minutes
.reduce(//zip with next
(ret,item,index,all)=>
(index!==all.length-1)//do not do last one, create [1,2][2,3][3,4]...
? ret.concat([[item,all[index+1]]])
: ret,
[]
);
return date =>{
//convert passed in date to a number (hour*60)+minutes
const passedInTime = (date.getHours()*60)+date.getMinutes();
return convertedBellTimes.reduce(
([ret,goOn],[low,high],index,all)=>
//if goOn is true and passedInTime between current and next bell item
(goOn && passedInTime<high && passedInTime>=low)
? [//found the item, return object and set goOn to false
{
current: index+1,
currentPeriod: bellTimes[index]+"-"+bellTimes[index+1],
remaining: high-passedInTime
},
false//set goOn to false, do not continue checking
]
: [ret,goOn],//continue looking or continue skipping (if goOn is false)
[
{current: 0, currentPeriod: "School is out", remaining: 0},//default value
true//initial value for goOn
]
)[0];//reduced to multiple values (value, go on) only need value
}
};
//some tests
const date = new Date();
//partially apply with some bell times
const schoolTime = getInfoSchoolTime(
[
"8:10", "9:02", "9:54", "9:59", "10:51",
"11:43", "11:58", "12:48", "13:35", "13:40",
"14:10", "14:10", "15:02", "15:54"
]
);
//helper to log time from a date
const formatTime = date =>
("0"+date.getHours()).slice(-2)+":"+("0"+date.getMinutes()).slice(-2);
date.setHours(11);
date.setMinutes(1);
console.log(formatTime(date),schoolTime(date));//11:01
date.setHours(15);
date.setMinutes(53);
console.log(formatTime(date),schoolTime(date));//15:53
date.setHours(23);
date.setMinutes(1);
console.log(formatTime(date),schoolTime(date));//23:01

Modify dataGrouping in Highcharts

Highcharts hour data aggregation flow
follows the next rules: 01 AM = 01:00 + 01:15 + 01:30 + 01:45. (example). So all points between current hour and the next one.
I want it to follow the rule: 01 AM = 00:00 + 00:15 + 00:30 + 00:45
I didn't find a possibility to do that in datagrouping options of library.
Now I'm thinking about hack to modify serie.groupedData object (adding 1 hour to time present there), but unfortunately, even though data is modified it still display old values in chart
chartConfiguration.xAxis[0].events = {
setExtremes(event) {
this.series.forEach(serie => {
if (serie.hasGroupedData && serie.currentDataGrouping.unitName == "hour") {
let groupedData = serie.groupedData.map(dataPiece => {
dataPiece.x = dataPiece.x + 3600000;
return dataPiece;
});
serie.update(groupedData);
}
})
}
};
This code changes x value of all the points to one hour earlier if 1 hour data grouping is applied:
chart: {
events: {
render: function() {
if (redrawEnabled) { // prevent infinte recursive loop - this.redraw() calls render event
redrawEnabled = false;
var series = this.series[0],
isHourUnit = series.currentDataGrouping.unitName === 'hour';
if (isHourUnit && !hourOffsetApplied) {
// change the data
series.setData(data.slice().map((p) => [p[0] - hour, p[1]]), false);
hourOffsetApplied = true;
} else if (!isHourUnit && hourOffsetApplied) {
// resotre the original data
series.setData(data, false);
hourOffsetApplied = false;
}
this.redraw();
redrawEnabled = true;
}
}
}
},
Live demo: http://jsfiddle.net/BlackLabel/z850035n/
If you change dataGrouping.units to ['day', [1]] point are displayed without time offset.

How to group array of dates to periods startdate-enddate? If one weekday is missing between dates then new period begins in Javascript

20.01.2017
23.01.2017
24.01.2017
25.01.2017
26.01.2017
27.01.2017
31.01.2017
01.02.2017
Lets say i have these dates. All those dates are workdays.
Output should be
20.01.2017-27.01.2017
and
31.01.2017-01.02.2017
Since 30 January is workday and so the first period is not continiuing and new period starts.
What is the best way to approach this.
I was thinking taking first date in array and putting it into a new array. Then comparing next date in array to the previous one if it's next day (ignoring weekends). If it is not nextday then take previous date and put it to array as end date and then start a new array of next period.
Get your first date (I'm supossing you have them ordered, as in your example data they are) and store it on a variable for the start date.
Store the same value also in another variable for the end date.
Now loop through your dates checking if current looped date is the next one after your current end date. If it's, store your current looped date into the end date variable and continue to the next loop. If it isn't return current start and end dates and store your currently looped date as a new period start date, go on until loop ends and return current variables.
This would be my approach, though not the shortest or maybe best way of facing this. Just take it as an idea
var array = [
"20.01.2017",
"23.01.2017",
"24.01.2017",
"25.01.2017",
"26.01.2017",
"27.01.2017",
"31.01.2017",
"01.02.2017"
];
var isNextDay = function(day, nextDay) {
var day1 = new Date(day.slice(3, 6) + day.slice(0, 3) + day.slice(6)); //had to format the date this way to make a valid date
day1.setDate(day1.getDate() + 1); //sets the next day, nextday of 30 or 31(last day of month) is 1
var day2 = new Date(nextDay.slice(3, 6) + nextDay.slice(0, 3) + nextDay.slice(6));
if (day1.getTime() === day2.getTime()) {
return true;
} else {
return false;
}
}
var dateGroup = function(dateStrings) {
var res = [];
var aux = dateStrings[0] + "-";
for (var i = 1; i < dateStrings.length; i++) {
if (!isNextDay(dateStrings[i - 1], dateStrings[i])) {
aux += dateStrings[i - 1];
res.push(aux);
aux = dateStrings[i] + "-";
}
}
aux += dateStrings[dateStrings.length - 1];
res.push(aux); //this is because the last one never gets pushed
return res;
}
var output = dateGroup(array);
You can loop over the dates and calculate what the string for the next date should look like, then compare to see if it's the same. If not, end the previous period and start a new one.
You can use a library to parse and format the dates, but simple functions to do the job are just a couple of lines, e.g.
var dates = ['20.01.2017','23.01.2017','24.01.2017',
'25.01.2017','26.01.2017','27.01.2017',
'31.01.2017','01.02.2017'];
/* Parse date in format D/M/YYYY
** #param {string} s - date to parse lke 23.1.2017
** #returns {Date}
*/
function parseDMY(s) {
var b = s.split(/\D/);
return new Date(b[2], b[1]-1, b[0]);
}
/* Format a date in DD/MM/YYYY with supplied separator
** #param {Date} date - date to format
** #param {string} s - separator, default is /
** #returns {string} date formatted as DD/MM/YYYY with supplied separator
*/
function formatDMY(date, s) {
s = s || '/';
function z(n){return (n<10?'0':'')+n}
return [z(date.getDate()),z(date.getMonth()+1),
date.getFullYear()].join(s);
}
/* Create array of date ranges in DD.MM.YYYY-DD.MM.YYYY format
** #param {Array} data - array of date strings in DD.MM.YYYY format
** #returns {Array} array of range strings in DD.MM.YYYY-DD.MM.YYYY format
*/
function createRanges(data) {
var result = [];
var previous;
data.forEach(function(s, i) {
var previous, previousNext, current, range;
// If on first loop, create a range using first value
if (i == 0) {
result.push(s + '-' + s);
// Otherwise, get end date of last range and add one day
} else {
previous = result[result.length-1].split('-')[1];
previousNext = parseDMY(previous);
previousNext.setDate(previousNext.getDate() + 1);
previousNext = formatDMY(previousNext,'.');
// If current date is same as previousNext, update range.
// Otherwise, start a new range
if (s == previousNext) {
range = result[result.length-1];
result[result.length-1] = range.split('-')[0] + '-' + s;
} else {
result.push(s + '-' + s);
}
}
});
// Remove zero day ranges. Could do this by checking last range
// when creating a new one but seems simpler to do it here
result = result.filter(s=>!(s.split('-')[0] == s.split('-')[1]));
return result;
}
console.log(createRanges(dates));
However, a library like moment.js will help with parsing, formatting and arithmetic.
Same as made by Leandro, but made for an array with Date objects and with using moment.js
function groupDates(dates) {
const res = [];
const isNextDay = (day, nextDay) => moment(day).add(1, 'day').isSame(nextDay, 'day');
const format = "DD.MM.YYYY";
let aux = moment(dates[0]).format(format) + "-";
for (let i = 1; i < dates.length; i++) {
if (!isNextDay(dates[i - 1], dates[i])) {
aux += moment(dates[i - 1]).format(format);
res.push(aux);
aux = moment(dates[i]).format(format) + "-";
}
}
aux += moment(dates[dates.length - 1]).format(format);
res.push(aux);
return res;
}
My solution with Luxon lib
const DateTime = luxon.DateTime;
const test = [
"2022-06-23",
"2022-06-24",
"2022-06-25",
"2022-06-26",
"2022-06-27",
"2022-06-28",
"2022-06-29",
"2022-05-02",
"2022-05-03",
"2022-05-05",
"2022-05-04",
"2022-05-06",
"2022-05-07",
"2022-05-08",
];
function getRanges(datesArr) {
const periods = [];
let ix = 0;
const dates = datesArr.map((d) => DateTime.fromSQL(d));
dates.sort();
dates.forEach((date, index) => {
if (index === 0) {
periods.push([
date,
]);
} else if (date.diff(dates[index - 1], [ 'days' ]).days === 1) {
periods[ix].push(date);
} else {
ix += 1;
periods.push([ date ]);
}
})
return periods;
}
console.log(getRanges(test));
<script src="https://cdnjs.cloudflare.com/ajax/libs/luxon/2.4.0/luxon.min.js"></script>
Then you can get first and last elements from each ranges

Find the next closest date in MM/DD/YYYY format JavaScript

I have an array of dates formatted as MM/DD/YYYY. I need to find the next closest date in the future starting from today. Say today was 1/22/2016 then 2/19/2016 would return.
2/3/2015
7/5/2015
1/21/2016
2/19/2016
7/1/2016
I've tried doing substrings to get the month, day, year separate and attempting a sort based off those values but surely there has to be a better way.
There is no need for a sorting algorithm. You only need to iterate once and find the closest date that is greater or equals today.
Pseudocode
closest <- infinity
foreach date in dates:
if (date >= now and date < closest) then
closest <- d
return closest
JavaScript
const dates = [
'2/3/2035',
'7/5/2035',
'1/21/2036',
'2/19/2036',
'7/1/2036',
'10/22/2039',
'08/12/2039',
];
const now = new Date();
let closest = Infinity;
dates.forEach(function(d) {
const date = new Date(d);
if (date >= now && (date < new Date(closest) || date < closest)) {
closest = d;
}
});
console.log(closest);
Personally I would use a library such as the very good Moment.JS library, to handle all the horrible complexity of dates.
It has a difference method:
http://momentjs.com/docs/#/displaying/difference/
e.g.
var a = moment([2007, 0, 29]);
var b = moment([2007, 0, 28]);
a.diff(b) // 86400000
It would then be trivial to Math.min() the differences of each date in your list.
There's also a moment.min, which might shortcut this entirely, if all your dates are in the future already:
http://momentjs.com/docs/#/get-set/min/
A naïve implementation would be to parse each date as a string and sort them in ascending order. Then, remove any dates that are in the past, and get the first child of the array of remaining dates. See this jsbin example:
var dates = [
'2/3/2015',
'7/5/2015',
'1/21/2016',
'2/19/2016',
'7/1/2016'
];
// parse each string as a Date object and sort them in ascending order
function sortDates(dates) {
return dates.map(function(date) {
return new Date(date).getTime();
}).sort(function(a, b) {
return a - b;
});
}
var orderedDates = sortDates(dates);
// remove any dates in the past, and get the first child of the array of remaining dates
var nextDate = orderedDates.filter(function(date) {
return (Date.now() - date) > 0;
})[0];
Keep in mind that this depends on the format of the date string that you pass to the Date object (in other words, is 1/12/2015 January 12th, or December 1st? JavaScript will parse it as January 12th.
You can use while loop, new Date()
var dates = ["2/3/2015","7/5/2015","1/21/2016","2/19/2016","7/1/2016"]
, d = "1/22/2016", n = -1, res = null;
while (++n < dates.length && new Date(dates[n]) < new Date(d));
res = dates[n] || d;
console.log(res)
Lots of answers, one more can't hurt.
Date strings should always be manually parsed. A library can help, but if you only have a single format, a simple function is all that's required.
The following uses reduce to loop over the array of dates and finds the closest future date. If no date is in the future, it returns null.
The returned value is the string from the array, not a Date.
function parseMDY(s) {
var b = (s || '').split(/\D/);
return new Date(b[2], b[0]-1, b[1])
}
function getClosestDateToToday(arr) {
var now = new Date();
now.setHours(23,59,59);
return arr.reduce(function (acc, s) {
var d = parseMDY(s);
return d < now? acc : (acc && d > parseMDY(acc)? acc : s);
}, null);
}
var dates = ['2/3/2015', '7/5/2015','1/21/2016',
'2/19/2016','7/1/2016'];
document.write(getClosestDateToToday(dates));
This really depends upon your dates and data structures (the ones shown in original example are not so great for me).
From the other answers...
To take the example from Josh, you could also keep a pointer to which date you are using, or simply shift off of a sorted queue of dates to make it work, but it's really adding noise to your code, disrupting the purpose.
Frederik.L answer is really beautiful code, but it would still have to be executed multiple times, so I cannot recommend it.
Feedback warning
I've been given feedback in comments that Date.parse can behave inconsistently. I'll move to passing a date parsing callback function, and demonstrate Date.UTC usage in the callback for OP-specific date format. Please be careful when defining your own callbacks, and please do not copy-paste.
Suggestion
I'd suggest utilizing Date functions i.e. Date.parse; but also try where possible to get data sources sorted without needing application-level sorting. Then you can store-once and step through the array using array.shift() or similar;
Ideally also YYYY-MM-DD
Four-Digit Year
Two-Digit Month
Two-Digit Day
... (continue from least occurring to most occurring)
sample code
var dates = [
'2/3/2015',
'7/5/2015',
'7/1/2016',
'1/21/2016',
'2/19/2016'
]; // unsorted garbage dates
var DateList = function( dateList, getDate ) {
var sortedDates = dateList.sort( function(a, b) {
return getDate(a) - getDate(b);
});
this.next = function() {
var dt = sortedDates.shift();
sortedDates.push(dt); // comment to remove cyclical nature
return dt;
}
};
// specific implementation parser for this format
var getDisgustingDateFormat = function(dStr) {
var dParts = dStr.split('/');
return new Date(Date.UTC(dParts[2],dParts[0],dParts[1]));
};
var dl = new DateList( dates, getDisgustingDateFormat );
Usage
dl.next(); // "2/3/2015"
dl.next(); // "7/5/2015"
dl.next(); // "1/21/2016"
dl.next(); // "2/19/2016"
dl.next(); // "7/1/2016"
dl.next(); // "2/3/2015"
Hope this helps (Updated for clarity)
What about this version using for of and momentjs:
const getClosestFutureDate = (dates) => {
if (dates.length === 0) {
return null;
}
let minDiff = 0;
for (const date of dates) {
minDiff += minDiff + 30;
var currentDate = moment(date);
if (currentDate.isAfter(moment()) && currentDate.diff(moment(), "days") <= minDiff) {
break;
}
}
return currentDate;
};
Assuming now = 2019-08-21
console.log(getClosestFutureDate(["2019-05-07", "2019-06-01", "2019-07-13", "2019-11-09", "2019-11-10", "2019-11-11"]));
// 2019-11-09
I am fan of momentjs, but this can be easily refactored to use only vanilla Date.
const FindDate = (date, allDate) => {
// moment().diff only works on moment(). Make sure both date and elements in allDate list is in moment
let nearestDate = -1;
allDate.some(d => {
const currentDate = moment(d)
const difference = currentDate.diff(date); // Or date.diff(currentDate) depending on what you're trying to find
if(difference >= 0){
nearestDate = d
}
});
console.log(nearestDate)
}
In Livescript:
x =
* "2/3/2015"
* "7/5/2015"
* "1/21/2016"
* "2/19/2016"
* "7/1/2016"
sim-unix-ts = (date-str) ->
# Simulate unix timestamp like concatenating
# convert "MM/DD/YYYY" to YYYYMMDD (integer)
# so we can simply compare these integers
[MM, DD, YYYY] = date-str.split "/"
MM = "0#{MM}".slice -2 # apply zero padding
DD = "0#{DD}".slice -2 # apply zero padding
parse-int "#{YYYY}#{MM}#{DD}"
today = sim-unix-ts "2/18/2016"
date-list = [sim-unix-ts(..) for x]
# find next date
next-dates = [.. for date-list when .. > today]
next-date = next-dates.0
next-date-orig = x[date-list.index-of next-date]
alert [next-date, next-date-orig]
..in Javascript:
var x, simUnixTs, today, dateList, res$, i$, x$, len$, nextDates, y$, nextDate, nextDateOrig;
x = ["2/3/2015", "7/5/2015", "1/21/2016", "2/19/2016", "7/1/2016"];
simUnixTs = function(dateStr){
var ref$, MM, DD, YYYY;
ref$ = dateStr.toString().split("/"), MM = ref$[0], DD = ref$[1], YYYY = ref$[2];
MM = ("0" + MM).slice(-2);
DD = ("0" + DD).slice(-2);
return parseInt(YYYY + "" + MM + DD);
};
today = simUnixTs("2/18/2016");
res$ = [];
for (i$ = 0, len$ = x.length; i$ < len$; ++i$) {
x$ = x[i$];
res$.push(simUnixTs(x$));
}
dateList = res$;
res$ = [];
for (i$ = 0, len$ = dateList.length; i$ < len$; ++i$) {
y$ = dateList[i$];
if (y$ > today) {
res$.push(y$);
}
}
nextDates = res$;
nextDate = nextDates[0];
nextDateOrig = x[dateList.indexOf(nextDate)];
alert([nextDate, nextDateOrig]);

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