如何使用 moment.js 减去 1 个月？

Question

I want to subtract 1 month from a given date in (DD/MM/YYYY) format, but when I do that using moment.js, it gives me the result as 01/12/2020. How can I resolve this? Basically when I click on the left-arrow, the month should be subtracted by 1 every

var startOfMonth = moment().clone().startOf('month').format('DD/MM/YYYY');

leftArrow.on('click', function(){
    var start = moment(startOfMonth).subtract(1, 'months').format("DD/MM/YYYY");
});

Answer 1

How can I subtract one month using moment.js?

tl,dr;

moment(date).add(-1, 'months');
// or:  moment(date).subtract(1, 'months');

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initial answer:

Here's a basic example.

It stores the date as a moment object, which you then modify by adding or subtracting a month without ever caring what its current value is. You could also store it as a JavaScript Date object, which is useful when you have to communicate it to an external entity (a db, the browser, etc...).

Take away points:

• the date is not stored as text
• the mods to the date are minimal
• the date is parsed to text in only one place: before updating DOM (in setDate function)

 // set initial date let storedDate = moment.now(); // update DOM setDate(storedDate); function setDate(date) { document.getElementById('text').innerText = moment(date).format('MMMM YYYY'); } function addMonths(months) { // change stored date storedDate = moment(storedDate).add(months, 'months'); // update DOM setDate(storedDate); }

 #text { min-width: 120px; text-align: center; display: inline-block } button { cursor: pointer; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script> <div> <button onclick="addMonths(-1)">&lt;</button> <span id="text"></span> <button onclick="addMonths(1)">&gt;</button> </div>

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