Moment.js sets dates to 1 day behind

问题

I am using 2.22.1 to format dates.

When i put in a date that comes from a date selector, moment will put the date back one day. For example, when I try to format a date in the following way:

Example 1:

const day = new Date(value).getDate();
const month = new Date(value).getMonth();
const fullYear = new Date(value).getFullYear();
console.log('day', day); // 7
console.log('month', month); // 5
console.log('fullYear', fullYear); //2018

Formatting function:

moment.utc(new Date(month + ' ' + day + ' ' + fullYear), 'MM-DD-YYYY').format('DD-MM-YY')

Output: 06-05-18

Expected: 07-05-18

Example 2:

Input: Thu May 31 2018 00:00:00 GMT+0100 (GMT Summer Time)

Formatting function:

moment.utc(new Date(value)).format('DD-MM-YY')

Output: 30-05-18 Expected: 31-05-18

回答1:

moment.utc will convert the input to universal time.
you are running new Date(...) with an output that's based on GMT +1

if you think about this, it makes total sense.
your output is 30-05-18 because it's 11 PM / 23:00 o'clock on the previous day.

this how ever would in fact work:

moment('05-06-2018', 'MM-DD-YYYY').format('DD-MM-YY')
// alternatively this:
moment.utc('05-06-2018', 'MM-DD-YYYY').format('DD-MM-YY')

and output: "06-05-18"

one of the reasons moment.js exists is to get rid of Date in your code all together.
please just read the documentation on how to properly use moment.

来源：https://stackoverflow.com/questions/50473932/moment-js-sets-dates-to-1-day-behind

标签

node.js

momentjs