How to convert a Date to the first of next month in JavaScript?

Question

I have an HTML file and it has a field to input the date and this html file is interacting with a JavaScript file.

So, what i want to do is as soon as i enter the date input it should get converted to the first date of next month.

for example: if I am providing the date input as 21/05/2020 (dd/mm/yyyy format) it should get converted to 01/06/2020 (dd/mm/yyyy format) i.e, first date of next month.

can anyone help with the JavaScript logic to do this?

Please ignore the previous date format . The date format should be mm/dd/yyyy — Vinay, Aug 08 '20 at 07:32

dave · Answer 1 · 2020-08-08T07:56:58.380

Just increment the month by 1, and set the date to 1:

document.getElementById('demo').addEventListener('blur', function({target}) {
    const { value } = target;
    const d = new Date(value);
    d.setMonth(d.getMonth() + 1)
    d.setDate(1);   
    const date = d.toLocaleDateString('en-US', {
        year: 'numeric',
        month: "2-digit",
        day: "2-digit"
    });
    console.log(date)
    const [month, day, year] = date.split('/');
    target.value = [year, month, day].join('-');
});

<input type="date" id="demo"/>

score 0 · Answer 2 · answered Aug 08 '20 at 07:33

0

Use moment library

moment('21/05/2020', "dd/mm/yyyy").add(1, 'M').startOf("month")

answered Aug 08 '20 at 07:33

aaditya

555
7
19

score 0 · Answer 3 · answered Aug 08 '20 at 07:45

Below is the plain JS implementation.

const d = new Date("05/21/2020")

const firstDayOfNextMonth = (str) => {
  const d = new Date(str)
  const month = d.getMonth()

  d.setMonth(month + 1)
  d.setDate(1)

  const resDate = String(d.getMonth() + 1).padStart(2, "0")
  const resMonth = String(d.getDate()).padStart(2, "0")
  const resYear = d.getFullYear()
  return `${resMonth}/${resDate}/${resYear}`
}

console.log(firstDayOfNextMonth("05/21/2020"))
console.log(firstDayOfNextMonth("12/21/2020"))

How to convert a Date to the first of next month in JavaScript?

3 Answers3