您可以创建一个: -
Date.prototype.addDays = function(days) {
var date = new Date(this.valueOf());
date.setDate(date.getDate() + days);
return date;
}
var date = new Date();
alert(date.addDays(5));
如果需要,这会自动增加月份。例如:
8/31 + 1 天将成为9/1 。
直接使用setDate
的问题在于它是一个变异器,最好避免这种情况。 ECMA 认为将Date
视为可变类而不是不可变结构是合适的。
正确答案 :
function addDays(date, days) {
var result = new Date(date);
result.setDate(result.getDate() + days);
return result;
}
答案不正确 :
这个答案有时会提供正确的结果,但通常会返回错误的年份和月份。此答案唯一有效的时间是您添加天数的日期恰好具有当前年份和月份。
// Don't do it this way!
function addDaysWRONG(date, days) {
var result = new Date();
result.setDate(date.getDate() + days);
return result;
}
Proof / Example
// Correct
function addDays(date, days) {
var result = new Date(date);
result.setDate(result.getDate() + days);
return result;
}
// Bad Year/Month
function addDaysWRONG(date, days) {
var result = new Date();
result.setDate(date.getDate() + days);
return result;
}
// Bad during DST
function addDaysDstFail(date, days) {
var dayms = (days * 24 * 60 * 60 * 1000);
return new Date(date.getTime() + dayms);
}
// TEST
function formatDate(date) {
return (date.getMonth() + 1) + '/' + date.getDate() + '/' + date.getFullYear();
}
$('tbody tr td:first-child').each(function () {
var $in = $(this);
var $out = $('<td/>').insertAfter($in).addClass("answer");
var $outFail = $('<td/>').insertAfter($out);
var $outDstFail = $('<td/>').insertAfter($outFail);
var date = new Date($in.text());
var correctDate = formatDate(addDays(date, 1));
var failDate = formatDate(addDaysWRONG(date, 1));
var failDstDate = formatDate(addDaysDstFail(date, 1));
$out.text(correctDate);
$outFail.text(failDate);
$outDstFail.text(failDstDate);
$outFail.addClass(correctDate == failDate ? "right" : "wrong");
$outDstFail.addClass(correctDate == failDstDate ? "right" : "wrong");
});
body {
font-size: 14px;
}
table {
border-collapse:collapse;
}
table, td, th {
border:1px solid black;
}
td {
padding: 2px;
}
.wrong {
color: red;
}
.right {
color: green;
}
.answer {
font-weight: bold;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<table>
<tbody>
<tr>
<th colspan="4">DST Dates</th>
</tr>
<tr>
<th>Input</th>
<th>+1 Day</th>
<th>+1 Day Fail</th>
<th>+1 Day DST Fail</th>
</tr>
<tr><td>03/10/2013</td></tr>
<tr><td>11/03/2013</td></tr>
<tr><td>03/09/2014</td></tr>
<tr><td>11/02/2014</td></tr>
<tr><td>03/08/2015</td></tr>
<tr><td>11/01/2015</td></tr>
<tr>
<th colspan="4">2013</th>
</tr>
<tr>
<th>Input</th>
<th>+1 Day</th>
<th>+1 Day Fail</th>
<th>+1 Day DST Fail</th>
</tr>
<tr><td>01/01/2013</td></tr>
<tr><td>02/01/2013</td></tr>
<tr><td>03/01/2013</td></tr>
<tr><td>04/01/2013</td></tr>
<tr><td>05/01/2013</td></tr>
<tr><td>06/01/2013</td></tr>
<tr><td>07/01/2013</td></tr>
<tr><td>08/01/2013</td></tr>
<tr><td>09/01/2013</td></tr>
<tr><td>10/01/2013</td></tr>
<tr><td>11/01/2013</td></tr>
<tr><td>12/01/2013</td></tr>
<tr>
<th colspan="4">2014</th>
</tr>
<tr>
<th>Input</th>
<th>+1 Day</th>
<th>+1 Day Fail</th>
<th>+1 Day DST Fail</th>
</tr>
<tr><td>01/01/2014</td></tr>
<tr><td>02/01/2014</td></tr>
<tr><td>03/01/2014</td></tr>
<tr><td>04/01/2014</td></tr>
<tr><td>05/01/2014</td></tr>
<tr><td>06/01/2014</td></tr>
<tr><td>07/01/2014</td></tr>
<tr><td>08/01/2014</td></tr>
<tr><td>09/01/2014</td></tr>
<tr><td>10/01/2014</td></tr>
<tr><td>11/01/2014</td></tr>
<tr><td>12/01/2014</td></tr>
<tr>
<th colspan="4">2015</th>
</tr>
<tr>
<th>Input</th>
<th>+1 Day</th>
<th>+1 Day Fail</th>
<th>+1 Day DST Fail</th>
</tr>
<tr><td>01/01/2015</td></tr>
<tr><td>02/01/2015</td></tr>
<tr><td>03/01/2015</td></tr>
<tr><td>04/01/2015</td></tr>
<tr><td>05/01/2015</td></tr>
<tr><td>06/01/2015</td></tr>
<tr><td>07/01/2015</td></tr>
<tr><td>08/01/2015</td></tr>
<tr><td>09/01/2015</td></tr>
<tr><td>10/01/2015</td></tr>
<tr><td>11/01/2015</td></tr>
<tr><td>12/01/2015</td></tr>
</tbody>
</table>
var today = new Date();
var tomorrow = new Date();
tomorrow.setDate(today.getDate()+1);
要小心,因为这可能很棘手。设置 “明天” 时,它只能起作用,因为它的当前值与 “今天” 的年份和月份相匹配。但是,设置为 “32” 之类的日期数字通常仍可正常工作,以便将其移至下个月。