#JavaScript 、JQuery怎么获取当前系统时间，及指定日期时间

1.JQuery获取当前日期

var now = new Date();
now = new Date(now.getTime() + 86400000);
var year= now.getFullYear(), month= (now.getMonth() + 1).toString(), day = now .getDate().toString();
if (month.length == 1) {
month= '0' + month;
}
if (day .length == 1) {
    day = '0' + day ;
}
var dates=([year, month, day ].join('-'));
console.log(dates);

结果如图：

2.JQuery获取当前月份的第一天与倒数第二天

        var now = new Date();
        var month = now.getMonth() + 1;//js获取到的是月份是 0-11 所以要加1
        var year = now.getFullYear();
        var nextMonthFirstDay = new Date([year,month + 1,1].join('-')).getTime();
        var oneDay = 1000 * 24 * 60 * 60;
        var monthLast = new Date(nextMonthFirstDay - oneDay).getDate()
		var nowMonthFirstDay=[year,month,1].join('-')
		var nowMonthLastSecondDay=[year,month,monthLast].join('-')
        console.log(nowMonthFirstDay);//当前月的第一天
        console.log(nowMonthLastSecondDay)//当前月的倒数第二天

结果如图：

2.JQuery获取当前月份的某一天如当前月的15号

     var now = new Date();
        var month = now.getMonth() + 1;//js获取到的是月份是 0-11 所以要加1
        var year = now.getFullYear();
        var nextMonthFirstDay = new Date([year,month + 1,1].join('-')).getTime();
        var oneDay = 1000 * 24 * 60 * 60*14;
        var monthLast = new Date(nextMonthFirstDay + oneDay).getDate()
		var nowMonthFifteenthDay=[year,month,monthLast].join('-')
        console.log(nowMonthFifteenthDay)//当前月的15号

希望以上内容可以帮助到你！
如有其他方法，欢迎交流学习！