php 准确遍历时间（月份）

function GetMonth($sign="1")
{
    //得到系统的年月
    $tmp_date=date("Ym");
    //切割出年份
    $tmp_year=substr($tmp_date,0,4);
    //切割出月份
    $tmp_mon =substr($tmp_date,4,2);
    $tmp_nextmonth=mktime(0,0,0,$tmp_mon+1,1,$tmp_year);
    $tmp_forwardmonth=mktime(0,0,0,$tmp_mon-1,1,$tmp_year);
    if($sign==0){
        //得到当前月的下一个月
        return $fm_next_month=date("Ym",$tmp_nextmonth);
    }else{
        //得到当前月的上一个月
        return $fm_forward_month=date("Ym",$tmp_forwardmonth);
    }
}

 

http://alfred-long.iteye.com/blog/1613227