JS计算前一天或后一天，前一月后一月，上一天下一下，上一月下一月。
方法一：
function ktkGetNextMonth(currentDate, scaleStep) {
//scaleStep = 1 向后计算后一个月
//scaleStep = -1 向前计算前一个月
for(var minIncrements = 1;; minIncrements++) {
var nextDate = new Date(currentDate);
nextDate.setHours(currentDate.getHours() + scaleStep * minIncrements);
if(nextDate.getMonth() != currentDate.getMonth()) {
return nextDate;
}
}
}
function ktkGetNextDate(currentDate, scaleStep) {
//scaleStep = 1 向后计算后一天
//scaleStep = -1 向前计算前一天
for(var minIncrements = 1;; minIncrements++) {
var nextDate = new Date(currentDate);
nextDate.setHours(currentDate.getHours() + scaleStep * minIncrements);
if(nextDate.getDate() != currentDate.getDate()) {
return nextDate;
}
}
}
方法二：
function GetDateStr(AddDayCount) {
var dd = new Date();
dd.setDate(dd.getDate()+AddDayCount);//获取AddDayCount天后的日期
var y = dd.getFullYear();
var m = dd.getMonth()+1;//获取当前月份的日期
var d = dd.getDate();
return y+"-"+m+"-"+d;
}
document.write("前天："+GetDateStr(-2));
document.write("<br />昨天："+GetDateStr(-1));
document.write("<br />今天："+GetDateStr(0));
document.write("<br />明天："+GetDateStr(1));
document.write("<br />后天："+GetDateStr(2));
document.write("<br />大后天："+GetDateStr(3));