//减去或增加几天的日期返回
//today:日期
//addDayCount:增加或减去的天数
function getDateStr(today, addDayCount) {
var dd;
if (today) {
dd = new Date(today);
} else {
dd = new Date();
}
dd.setDate(dd.getDate() - addDayCount); //获取AddDayCount天后的日期 ,增加用+,减去用-
var y = dd.getFullYear();
var m = dd.getMonth() + 1; //获取当前月份的日期
var d = dd.getDate();
if (m < 10) {
m = '0' + m;
};
if (d < 10) {
d = '0' + d;
};
return y + "-" + m + "-" + d;
}