这是一个计算2000年01月01日起到指定日的天数的函数 <br> (算头也算尾)日期格式为：YYYY-MM-DD <br> <?php //    计算从2000年01月01日开始到某日的天数 function cal_start2end($end_day,$start_day) { $start_day=ereg_replace("-","",$start_day); $end_day=ereg_replace("-","",$end_day); if($end_day>=$start_day) {    //    截止日期大于开始日期     if(substr($end_day,0,4)==substr($start_day,0,4))         { if( is_int(substr($end_day,0,4)/4) )     $leap_day=29;    //leap year else     $leap_day=28; //            //同一年         if(substr($end_day,4,2)==substr($start_day,4,2))             { //            the same month               $endday_from_startday=$end_day-$start_day+1;             }         else             { //             not same month             switch (substr($end_day,4,2))                 {                 case "01":                         $endday_from_newyear=substr($end_day,6,2)+1;                         break;                 case "02":                         $endday_from_newyear=substr($end_day,6,2)+31;                         break;                 case "03":                         $endday_from_newyear=substr($end_day,6,2)+$leap_day+31;                         break;                 case "04":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*2;                         break;                 case "05":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*2+30;                         break;                 case "06":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*3+30;                         break;                 case "07":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*2+30*2;                         break;                 case "08":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*3+30*2;                         break;                 case "09":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*2;                         break;                 case "10":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*3;                         break;                 case "11":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*4;                         break;                 case "12":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*5;                         break;                 }             $endday_from_startday=$endday_from_newyear;             } return ($endday_from_startday);         }     else         { //        不同年！ $differ_year=substr($end_day,0,4)-substr($start_day,0,4); $how_int_4_floor=floor($differ_year/4)+1; // 向下取整 $how_int_4_ceil=ceil($differ_year/4)+1; // 向上取整 if($how_int_4_floor==$how_int_4_ceil)     $how_leap_year=$how_int_4_floor-1; else     $how_leap_year=$how_int_4_floor; $how_noleap_year=$differ_year-$how_leap_year; $differ_year2day=$how_noleap_year*365+$how_leap_year*366; if( is_int(substr($end_day,0,4)/4) )     $leap_day=29;    //leap year else     $leap_day=28;         if(substr($end_day,4,2)==substr($start_day,4,2))             { //            the same month               $endday_from_startday=$differ_year2day+ substr($end_day,4,2);             }         else             { //             not same month             switch (substr($end_day,4,2))                 {                 case "01":                         $endday_from_newyear=substr($end_day,6,2)+1;                         break;                 case "02":                         $endday_from_newyear=substr($end_day,6,2)+1+31;                         break;                 case "03":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31;                         break;                 case "04":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*2;                         break;                 case "05":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*2+30;                         break;                 case "06":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*3+30;                         break;                 case "07":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*2+30*2;                         break;                 case "08":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*3+30*2;                         break;                 case "09":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*2;                         break;                 case "10":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*3;                         break;                 case "11":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*4;                         break;                 case "12":                         $endday_from_newyear=substr($end_day,6,2)+1+$leap_day+31*5+30*5;                         break;                 } //End of switch     $endday_from_startday=$endday_from_newyear+$differ_year2day;     }    //End of  not same month   return ($endday_from_startday);         } //End of year }        //End of  $end_day>=$start_day } //End of function $start_day="2000-01-01"; $end_day="2011-01-01"; echo "您输入的是：".$end_day."<br> "; $endday_from_startday=cal_start2end($end_day,$start_day); echo "该日距离$start_day 共 ".$endday_from_startday." 天"; ?> <br><br><br><br>时间太少了，那位大虾可以修改为计算任意两日期之间的间隔最好！！！！！