<script>
    $('body').on('change','#agencyinvest-invest_time',function (res) {
        // console.log($(this).val())
        $('#agencyinvest-invest_profit_begin_time').val(calcuDate($(this).val(),45));
    });
    function calcuDate(date, plusDays) {
        var dateArray = date.split("-");
        var year = +dateArray[0];
        var month = +dateArray[1];
        var day = +dateArray[2];
        var oriDay = day;
        var secondMonthDays = ((year%4 === 0 && year%100 !== 0) || year%400 === 0) ? 29 : 28;
        while(plusDays>0) {
            oriDay = day;
            day += plusDays;
            switch(month) {
                case 4:
                case 6:
                case 9:
                case 11:
                    if(day > 30) {
                        plusDays -= (30-oriDay)+1;
                        month++;
                        day = 1;
                    } else {
                        plusDays = 0;
                    }
                    break;
                case 2:
                    if(day > secondMonthDays) {
                        plusDays -= (secondMonthDays-oriDay)+1;
                        month++;
                        day = 1;
                    } else {
                        plusDays = 0;
                    }
                    break;
                default:
                    if(day > 31) {
                        plusDays -= (31-oriDay)+1;
                        day = 1;
                        month++;
                    } else {
                        plusDays = 0;
                    }
            }
            if(month>12) {
                month = 1;
                year++;
            }
        }
        return year+'-'+month+'-'+day;
    }
</script>