Prashant Ingale

In this we will see date validation function written in PHP.
For using this function date has to be separated with “-” or “/” or u can change to your favorite one. If anyone have any queries or suggestions they are welcome.

function date_validate($datefield) {
	    // First check to see if the input ($datefield) is in one of the accepted formats
	    // Check for delimiters ("-" or "/") and put three fields into an array
	    if (strpos($datefield, "-")) {
	      $datesplit = explode("-", $datefield);
	    } elseif (strpos($datefield, "/")) {
	      $datesplit = explode("/", $datefield);
	    } else {
	        $date_err="Error: Invalid date field. No proper delimiters (- or /) found";
	        return false;
	    }
	    // Check for three input fields (month, day, year)
	    if (count($datesplit)>3) {
	        $date_err="Error: Invalid date field. Too many fields (".count($datesplit).") found";
	        return false;
	    }
	    // Put date array into single format
	    if (strlen($datesplit[2])==4) { // The year is listed last - switch fields around
	        $newdatesplit[0]=$datesplit[2]; // Move Year to first field
	        $newdatesplit[1]=$datesplit[0]; // Move Month to second field
	        $newdatesplit[2]=$datesplit[1]; // Move Day to third field
	        $datesplit=$newdatesplit;
	    } elseif (strlen($datesplit[0])==4) { // The year is first listed - do nothing
	        // nothing to be done
	    } else { // Date entered is not valid; could not find year field
	        $date_err=”Error: Date not valid. No Year field found (Year must be 4 digits)”;
	        return false;
	    }
	    // Main validation code
	    if ($datesplit[1]>12) { // No valid month field
	        $date_err=”Error: Invalid Month field (”.$datesplit[1].”) “;
	        return false;
	    } else {
	       switch ($datesplit[1]) { // Check number of days in a month
	           case 4:
	           case 6:
	           case 9:
	           case 11:
	                if ($datesplit[2]>30) {
	                    $date_err=”Error: Invalid # of days (”.$datesplit[2].”) for month “.$datesplit[1].” and year “.$datesplit[0];
	                    return false;
	                }
	                break;
	           case 2: // February Check
	                   if (($datesplit[0]/4)==(floor($datesplit[0]/4))) {
	                    if (($datesplit[0]/100)==(floor($datesplit[0]/100))) {
	                        if (($datesplit[0]==1600) or ($datesplit[0]==2000) or ($datesplit[0]==2400)) {
	                            if ($datesplit[2]>29) {
	                                $date_err=”Error: Invalid # of days (”.$datesplit[2].”) for month “.$datesplit[1].” and year “.$datesplit[0];
	                                return false;
	                            }
	                        } else {
	                            if ($datesplit[2]>28) {
	                                $date_err=”Error: Invalid # of days (”.$datesplit[2].”) for month “.$datesplit[1].” and year “.$datesplit[0];
	                                return false;
	                            }
	                        }
	                    } else {
	                        if ($datesplit[2]>29) {
	                            $date_err=”Error: Invalid # of days (”.$datesplit[2].”) for month “.$datesplit[1].” and year “.$datesplit[0];
	                            return false;
	                        }
	                    }
	                } else {
	                    if ($datesplit[2]>28) {
	                        $date_err=”Error: Invalid # of days (”.$datesplit[2].”) for month “.$datesplit[1].” and year “.$datesplit[0];
	                        return false;
	                    }
	                }
	                break;
	           default:
	                if ($datesplit[2]>31) {
	                    $date_err=”Error: Invalid # of days (”.$datesplit[2].”) for month “.$datesplit[1].” and year “.$datesplit[0];
	                    return false;
	                }
	        }
	      }
	          // Add leading zero if month or day field is only one character
	      if (strlen($datesplit[1])==1) {
	          $datesplit[1]=”0″.$datesplit[1];
	      }
	      if (strlen($datesplit[2])==1) {
	          $datesplit[2]=”0″.$datesplit[2];
	      }
	      // Create date field in MySQL format
	      $newdate=$datesplit[0].”-”.$datesplit[1].”-”.$datesplit[2];
	      return true;
	}