the function of to calculate the diff of date

hi, i am Yeekang ,i used PHP in web programming. I think PHP isn't eazy to calculate the diff of day (ex how many day between 2003/08/15 and 2003/09/21), so i write this function and wish it can help others handles problems efficiently. string datediff(DATE $date,STRING $parameter,CHAR $split) $date is date format which like 2003/03/16 YYYY/MM/DD $parameter can be Date format or int, if $parameter's type is Date ,function will calucute the diff between with $date else $date will increase/decrease the $parameter $split is the mark to split the DATE, i think it may be useless @_@ YeeKang <? function datediff($date,$parameter,$split="0"){ //setting the pattern for split use if($split!="0") //if the pattern have set by user $pattern = $split; else //found out the character which use at $date $pattern = substr(ereg_replace("[0-9]","",$date),0,1); $date1 = explode($pattern,$date); //split the date => year,month,day if(!checkdate($date1[1],$date1[2],$date1[0])) //check the date format return FALSE; if(is_numeric($parameter)){ //if you want to increase or decrease $timestamp = mktime(0,0,0,$date1[1],$date1[2]+$parameter,$date1[0]); return date("Y-m-d",$timestamp); //return the date after increase/decrease }else{ //just found out the diff of the date if($split=="0") $pattern = substr(ereg_replace("[0-9]","",$parameter),0,1); $date2 = explode($pattern,$parameter); //split the parameter => year,month,day if(!checkdate($date2[1],$date2[2],$date2[0])) //check the date format return FALSE; $timestamp1 = mktime(0,0,0,$date1[1],$date1[2],$date1[0]); //translate to timestamp $timestamp2 = mktime(0,0,0,$date2[1],$date2[2],$date2[0]); $diff = ($timestamp1 > $timestamp2)?($timestamp1 - $timestamp2):($timestamp2 - $timestamp1); return $diff/86400; //return the diff of the date } } echo "Today : ".date("Y-m-d")."<br>"; echo "datediff(date(\"Y-m-d\"),4) : ".datediff(date("Y-m-d"),4); echo "<br>"; echo "datediff(date(\"Y-m-d\"),-4) : ".datediff(date("Y-m-d"),-4); echo "<br>"; echo "datediff(date(\"Y-m-d\"),\"2003-02-21\") : ".datediff(date("Y-m-d"),"2003-02-21"); echo "<br>"; echo "datediff(date(\"Y@m@d\"),\"2003@08@21\",\"@\") : ".datediff(date("Y@m@d"),"2003@08@21","@"); echo "<br>"; echo "datediff(date(\"Y@m@d\"),\"2003$08$21\") : ".datediff(date("Y@m@d"),"2003$08$21"); ?> Today : 2003-08-18 datediff(date("Y-m-d"),4) : 2003-08-22 datediff(date("Y-m-d"),-4) : 2003-08-14 datediff(date("Y-m-d"),"2003-02-21") : 178 datediff(date("Y@m@d"),"2003@08@21","@") : 3 datediff(date("Y@m@d"),"2003$08$21") : 3 ------------------------------------------------- This mail sent through NCTU WebMail System: https://webmail.nctu.edu.tw