Javascript Date out by one day (the day before)-CodePudding

So I select two dates and build an array based on this.

For example:

var getDaysArray = function (s, e) { for (var a = [], d = new Date(s); d <= e; d.setDate(d.getDate()   1)) { a.push(new Date(d)); } return a; };
var daylist = getDaysArray(new Date(datefrom), new Date(dateto));

This returns (daylist) the following:

0: Thu Mar 31 2022 00:00:00 GMT 0800 (Australian Western Standard Time) {}
1: Fri Apr 01 2022 00:00:00 GMT 0800 (Australian Western Standard Time) {}
2: Sat Apr 02 2022 00:00:00 GMT 0800 (Australian Western Standard Time) {}
3: Sun Apr 03 2022 00:00:00 GMT 0800 (Australian Western Standard Time) {}
4: Mon Apr 04 2022 00:00:00 GMT 0800 (Australian Western Standard Time) {}
5: Tue Apr 05 2022 00:00:00 GMT 0800 (Australian Western Standard Time) {}

This is correct. However when I then build these dates:

const thesedays = daylist.map((v) => v.toISOString().slice(0, 10));

This returns (thesedays) the following:

0: "2022-03-30"
1: "2022-03-31"
2: "2022-04-01"
3: "2022-04-02"
4: "2022-04-03"
5: "2022-04-04"

So it is actually using the day before (March 30 instead of 31 and April 4 instead of 5)

It is the const of thesedays that I need to adjust ... just not sure how?

CodePudding user response：

I can think of two ways ...

const daylist = [
  new Date("2022-01-15T00:00:00"),
  new Date("2022-02-15T00:00:00"),
  new Date("2022-03-15T00:00:00"),
];
const thesedays = daylist.map((v) =>
    `${
        v.getFullYear().toString().padStart(4, "0")
    }-${
        (v.getMonth()   1).toString().padStart(2, "0")
    }-${
        v.getDate().toString().padStart(2, "0")
    }`
);


console.log(thesedays);

const daylist = [
  new Date("2022-01-15T00:00:00"),
  new Date("2022-02-15T00:00:00"),
  new Date("2022-03-15T00:00:00"),
];
const thesedays = daylist.map(
    (v) =>
        new Date(
            Date.parse(
                new Intl.DateTimeFormat("fr-CA", {
                    year: "numeric",
                    month: "2-digit",
                    day: "2-digit",
                }).format(v)
            )
        ).toISOString().split("T")[0]
);

console.log(thesedays)

The first code would be better off with a helper function

const daylist = [
  new Date("2022-01-15T00:00:00"),
  new Date("2022-02-15T00:00:00"),
  new Date("2022-03-15T00:00:00"),
];
const zf = (n, z=2) => n.toString().padStart(z, '0');
const thesedays = daylist.map((v) =>
    `${zf(v.getFullYear(), 4)}-${zf((v.getMonth()   1))}-${zf(v.getDate())}`
);


console.log(thesedays);