//It is very inconvenient to process dates in PHP. For example, find the month difference between two dates? What to do? //File name: date.inc.php3 //Before using these two functions, you must first convert the date or date time into the timestamp type. //For example: //$today=mktime(0,0,0,date("m"),date("d"),date("Y")); /****Simulating the dateadd function in sqlserver************ $part type: string Value range: year, month, day, hour, min, sec Representation: which part of the date to be added $n type: numerical representation : How much to increase, decide which part to increase based on $part. It can be a negative number. $datetime type: timestamp . Represents: the base of the increase. Return type: timestamp **************End****** ********/ function dateadd( $part,$n,$datetime){ $year=date("Y",$datetime); $month=date("m",$datetime); $day=date("d",$datetime); $ hour=date("H",$datetime); $min=date(“i”,$datetime); $sec=date(“s”,$datetime); $part=strtolower($part); $ret= 0; switch ($part) { case "year": $year+=$n; break; case "month": $month+=$n; break; case "day": $day+=$n; break; case "hour ": $hour+=$n; break; case "min": $min+=$n; break; case "sec": $sec+=$n; break; default: return $ret; break; } $ret=mktime( $hour,$min,$sec,$month,$day,$year); return $ret; } /****Simulate the datediff function in sqlserver************ $part type: string Value range: year, month, day, hour, min, sec Represents: which part of the date to be added $date1, $date2 type : timestamp Represents: Two dates to be compared Return type: Numeric **************End* (*************/ function datediff ($part,$date1,$date2){ //$diff= $date2-$date1; $year1=date("Y",$date1); $year2=date("Y",$date2); $month2=date("m",$date2); $month1=date( "m",$date1); $day2=date("d",$date2); $day1=date("d",$date1); $hour2=date("d",$date2); $hour1= date("d",$date1); $min2=date(“i”,$date2); $min1=date(“i”,$date1); $sec2=date(“s”,$date2); $ sec1=date("s",$date1); $part=strtolower($part); $ret=0; switch ($part) { case "year": $ret=$year2-$year1; break; case " month": $ret=($year2-$year1)*12+$month2-$month1; break; case "day": $ret=(mktime(0,0,0,$month2,$day2,$year2) -mktime(0,0,0,$month1,$day1,$year1))/(3600*24); break; case "hour": $ret=(mktime($hour2,0,0,$month2,$ day2,$year2)-mktime($hour1,0,0,$month1,$day1,$year1))/3600; break; case "min": $ret=(mktime($hour2,$min2,0,$ month2,$day2,$year2)-mktime($hour1,$min1,0,$month1,$day1,$year1))/60; break; case "sec": $ret=$date2-$date1; break; default: return $ret; break; } return $ret; } }