如何使用Day.js在浏览器中呈现日期？

<script src="https://cdn.jsdelivr.net/npm/dayjs@1.10.4/dayjs.min.js"></script>

// 获取当前日期和时间
var now = dayjs();
console.log(now.format('YYYY-MM-DD HH:mm:ss'));

// 格式化日期
var date = dayjs('2022-01-01');
console.log(date.format('dddd, MMMM D, YYYY'));

// 计算日期的差值
var diff = dayjs('2022-01-01').diff(dayjs(), 'days');
console.log(diff);

// 获取某个时间的相对时间
var relativeTime = dayjs('2022-01-01').fromNow();
console.log(relativeTime);

<div id="dateContainer"></div>

<script>
    var dateElement = document.getElementById('dateContainer');
    var formattedDate = dayjs().format('YYYY-MM-DD');
    dateElement.textContent = formattedDate;
</script>