js日期处理

//当前月第一天
function CurrentMonthFirst() {
    var date = new Date();
    var firstDate = date.setDate(1);
    return formatDate(firstDate)
}

//当前月最后一天
function CurrentMonthLast() {
    var date = new Date();
    var currentMonth = date.getMonth();
    var nextMonth = ++currentMonth;
    var nextMonthFirstDay = new Date(date.getFullYear(), nextMonth, 1);
    var oneDay = 1000 * 60 * 60 * 24;
    var lastDate = new Date(nextMonthFirstDay - oneDay);
    return formatDate(lastDate)
}

//日期格式化为yyyy-mm-dd
function formatDate(date) {
    var d = new Date(date),
        month = '' + (d.getMonth() + 1),
        day = '' + d.getDate(),
        year = d.getFullYear();

    if (month.length < 2) month = '0' + month;
    if (day.length < 2) day = '0' + day;

    return [year, month, day].join('-');
}