function getPreMonth(date) {
var arr = date.split('-');
var year = arr[0];
var month = arr[1];
var day = arr[2];
var days = new Date(year, month, 0);
days = days.getDate();
var year2 = year;
var month2 = parseInt(month) - 1;
if (month2 == 0) {
year2 = parseInt(year2) - 1;
month2 = 12;
}
var day2 = day;
var days2 = new Date(year2, month2, 0);
days2 = days2.getDate();
if (day2 > days2) {
day2 = days2;
}
if (month2 < 10) {
month2 = '0' + month2;
}
var t2 = year2 + '-' + month2 + '-' + day2;
return t2;
}
function getNextMonth(date) {
var arr = date.split('-');
var year = arr[0];
var month = arr[1];
var day = arr[2];
var days = new Date(year, month, 0);
days = days.getDate();
var year2 = year;
var month2 = parseInt(month) + 1;
if (month2 == 13) {
year2 = parseInt(year2) + 1;
month2 = 1;
}
var day2 = day;
var days2 = new Date(year2, month2, 0);
days2 = days2.getDate();
if (day2 > days2) {
day2 = days2;
}
if (month2 < 10) {
month2 = '0' + month2;
}
var t2 = year2 + '-' + month2 + '-' + day2;
return t2;
}