JavaScript Date setMonth()

将月份设置为 4（五月）：

const d = new Date();
d.setMonth(4);

下面有更多 "亲自试一试" 示例。

描述

setMonth() 方法设置日期对象的月份。

笔记：一月为 0，二月为 1，依此类推。

此方法也可用于设置月份中的某一天。

setMonth()是 ECMAScript1 (ES1) 功能。

所有浏览器均完全支持 ES1 (JavaScript 1997)：


Chrome	Edge	Firefox	Safari	Opera	IE
Yes	Yes	Yes	Yes	Yes	Yes

Date.setMonth( month, day)

Parameter	Description
month	Required. An integer representing the month Expected values are 0-11, but other values are allowed: -1 will result in the last month of the previous year 12 will result in the first month of the next year 13 will result in the second month of the next year
day	Optional. An integer representing the day of month Expected values are 1-31, but other values are allowed: 0 will result in the last day of the previous month -1 will result in the day before the last day of the previous month If the month has 31 days: 32 will result in the first day of the next month If the month has 30 days: 32 will result in the second day of the next month

Parameter

Description

month

Required. An integer representing the month

Expected values are 0-11, but other values are allowed:

day

Optional. An integer representing the day of month

Expected values are 1-31, but other values are allowed:

If the month has 31 days:

If the month has 30 days:

返回值：	一个数字，表示日期对象与 1970 年 1 月 1 日午夜之间的毫秒数
JavaScript 版本：	ECMA脚本1