I have a date range
Example Date Range:
const startDate = "2022-06-02";
const endDate = "2022-06-20";
I want to get those dates which comes on provided days array that falls between startDate & endDate
Example Array of Days:
["tuesday", "friday", "saturday"]
The expected result is :
2022-06-03
2022-06-04
2022-06-07
2022-06-10
2022-06-11
2022-06-14
2022-06-17
2022-06-18
Can anyone help me with this logic?
What I tried was so dirty, I put a loop on range of dates, and got the list of all dates, and then i put another loop to get name of day of each date, and then compared each day name in an array of days & pushed that date to new array
Here is the code (Which works perfectly fine) but I need better solution:
function getDaysArray(start, end) {
for(var arr=[],dt=new Date(start); dt<=new Date(end); dt.setDate(dt.getDate()+1)){
arr.push(helperClass.getDateTime(new Date(dt)).date);
}
return arr;
}
function getDayName (dateStr, locale){
var date = new Date(dateStr);
return date.toLocaleDateString(locale, { weekday: 'long' });
}
var days = ["tuesday", "friday", "saturday"];
var getAllDates = getDaysArray("2022-06-02", "2022-06-20");
var getDates = [];
for(var i = 0; i < getAllDates.length; i++){
if(days.includes(getDayName(getAllDates[i]).toLowerCase())){
getDates.push(getAllDates[i])
}
}
If you can use an external library, the date-fns library provides some helpers for this:
parse - Return the date parsed from string using the given format string.eachDayOfInterval - Return the array of dates within the specified time interval.getDay - Get the day of the week of the given date.is* helpers - e.g. isSunday, isMonday, etc.So if you parse your start and end dates, get a full interval range, then filter it against the days, you'll have your list.
import("https://unpkg.com/date-fns@2.28.0/esm/index.js").then(({ eachDayOfInterval, getDay, parse }) => {
const startDate = parse("2022-06-02", "yyyy-MM-dd", new Date());
const endDate = parse("2022-06-20", "yyyy-MM-dd", new Date());
const daysOfWeek = ["sunday", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday"];
// Here is your list
const daysToFilterFor = ["tuesday", "friday", "saturday"];
const daysToFilterForIndex = daysToFilterFor.map((day) => daysOfWeek.indexOf(day));
const range = eachDayOfInterval({
start: startDate,
end: endDate,
}).filter((day) => daysToFilterForIndex.includes(getDay(day)));
console.log(range);
});Details are commented in example
// Array of days to filter
const daysOff = ["Tuesday", "Friday", "Saturday"];
/**
* @desc Determine the specific dates of days that match a given array
* of weekdays within the range of two given dates.
* @param {string<date>} start - The first date of the range
* @param {string<date>} end - The last date of the range
* @param {array<string>} weekdays - The list of days used to find the dates
* @return {array<date>} An array of dates that correspond to weekdays
*/
function dateRanger(start, end, weekdays) {
// Convert dates into timestamps {number}
const A = Date.parse(start);
const Z = Date.parse(end);
// Seconds in a day
const day = 86400000;
// Determine number of days the range spans
const total = Math.floor(((Z - A) / day) + 1);
// Object that stores format settings for .toLocaleDateString()
const options = {
weekday: 'long',
year: 'numeric',
month: 'numeric',
day: 'numeric'
};
/*
- Instantiate an Array with room to fit the range of dates
- On each iteration instantiate a date based on the first date then format
it and add it's weekday using .toLocaleDateString()
- Return date string as an array of pairs using .split()
*/
const range = [...new Array(total)].map(
(_, i) => new Date(A + (day * i))
.toLocaleDateString('en-US', options)
.split(', ')
);
/*
- .flatMap() the first level of range to access the array of pairs
- On each iteration compare the first value of each pair (sub[0]) with the
given array (weekdays).
- If there's a match, return the second value (sub[1]) of each pair
- Otherwise return an empty array that gets flattened to zilch.
*/
return range.flatMap(
sub => weekdays.flatMap(
day => day === sub[0] ?
sub[1] : []
)
);
}
console.log(dateRanger('6-4-2022', '6-20-2022', daysOff));I know this may be not the best way to do it, but here how I did it
let days = { monday: 0, tuesday: 1, wednesday: 2, thursday: 3, friday: 4, saturday: 5, sunday: 6 };
const startDate = "2022-06-02";
const endDate = "2022-06-20";
function daysindates(arr) {
let stdate = startDate.substr(-2);
let endate = endDate.substr(-2);
let myarr = [],
result = [],
finalresult = [];
for (y of arr) {
for (let i = parseInt(stdate) + days[y]; i <= parseInt(endate); i += 7) {
result.push(i);
}
}
finalresult = result.map((item) => {
return "2022-06-" + item;
});
console.log(finalresult);
}
daysindates(["monday", "tuesday"]);