将日期转换为yyyy-mm-dd格式的最简单方法是这样做:

var date = new Date("Sun May 11,2014");
var dateString = new Date(date.getTime() - (date.getTimezoneOffset() * 60000 ))
                    .toISOString()
                    .split("T")[0];

工作原理:

new Date("Sun May 11,2014") converts the string "Sun May 11,2014" to a date object that represents the time Sun May 11 2014 00:00:00 in a timezone based on current locale (host system settings) new Date(date.getTime() - (date.getTimezoneOffset() * 60000 )) converts your date to a date object that corresponds with the time Sun May 11 2014 00:00:00 in UTC (standard time) by subtracting the time zone offset .toISOString() converts the date object to an ISO 8601 string 2014-05-11T00:00:00.000Z .split("T") splits the string to array ["2014-05-11", "00:00:00.000Z"] [0] takes the first element of that array

Demo

var date =新日期(“太阳5月11日”); var dateString =新日期(日期。 toISOString()。 斯普利特(“T”)[0]; 游戏机。log (dateString);

注意:

The first part of the code (new Date(...)) may need to be tweaked a bit if your input format is different from that of the OP. As mikeypie pointed out in the comments, if the date string is already in the expected output format and the local timezone is west of UTC, then new Date('2022-05-18') results in 2022-05-17. And a user's locale (eg. MM/DD/YYYY vs DD-MM-YYYY) may also impact how a date is parsed by new Date(...). So do some proper testing if you want to use this code for different input formats.

只需利用内置的toISOString方法，将您的日期转换为ISO 8601格式:

let yourDate = new Date()
yourDate.toISOString().split('T')[0]

yourDate是你的日期对象。

编辑:@exbuddha在评论中写了这个来处理时区:

const offset = yourDate.getTimezoneOffset()
yourDate = new Date(yourDate.getTime() - (offset*60*1000))
return yourDate.toISOString().split('T')[0]

格式化并从hashmap数据中查找最大值和最小值:

var obj = {"a":'2001-15-01', "b": '2001-12-02' , "c": '2001-1-03'}; function findMaxMinDate(obj){ let formatEncode = (id)=> { let s = id.split('-'); return `${s[0]+'-'+s[2]+'-'+s[1]}`} let formatDecode = (id)=> { let s = id.split('/'); return `${s[2]+'-'+s[0]+'-'+s[1]}`} let arr = Object.keys( obj ).map(( key )=> { return new Date(formatEncode(obj[key])); }); let min = new Date(Math.min.apply(null, arr)).toLocaleDateString(); let max = new Date(Math.max.apply(null, arr)).toLocaleDateString(); return {maxd: `${formatDecode(max)}`, mind:`${formatDecode(min)}`} } console.log(findMaxMinDate(obj));

2021年的解决方案使用Intl。

现在所有浏览器都支持新的Intl对象。 您可以通过选择使用所需格式的“区域设置”来选择格式。

瑞典语言环境使用的格式是"yyyy-mm-dd":

// Create a date
const date = new Date(2021, 10, 28);

// Create a formatter using the "sv-SE" locale
const dateFormatter = Intl.DateTimeFormat('sv-SE');

// Use the formatter to format the date
console.log(dateFormatter.format(date)); // "2021-11-28"

使用Intl的缺点:

使用此方法不能“取消格式化”或“解析”字符串 你必须搜索所需的格式(例如在维基百科上)，不能使用像“yyyy-mm-dd”这样的格式字符串。

这对我来说很有效，如果需要测试，你可以直接将它粘贴到你的HTML中:

<script type="text/javascript">
    if (datefield.type!="date"){ // If the browser doesn't support input type="date",
                                 // initialize date picker widget:
        jQuery(function($){ // On document.ready
            $('#Date').datepicker({
                dateFormat: 'yy-mm-dd', // THIS IS THE IMPORTANT PART!!!
                showOtherMonths: true,
                selectOtherMonths: true,
                changeMonth: true,
                minDate: '2016-10-19',
                maxDate: '2016-11-03'
            });
        })
    }
</script>

我建议使用类似formatDate-js的东西，而不是每次都试图复制它。只需使用一个支持所有主要strftime操作的库。

new Date().format("%Y-%m-%d")