Subscription start date is required (recurring) - codeigniter

Question

i am trying to do Recurring Payments on my site. but i gettin a problem here.
its is giving ack=Fail
[TIMESTAMP] => 2012-06-21T04:36:01Z
[CORRELATIONID] => fe0a920b9dee5
[ACK] => Failure
[VERSION] => 65.1
[BUILD] => 3067390
[L_ERRORCODE0] => 11549
[L_SHORTMESSAGE0] => Start Date is required
[L_LONGMESSAGE0] => Subscription start date is required
[L_SEVERITYCODE0] => Error
while my code for the reoccuring which i am passing is
function DoRecuringPayment($paymentInfo=array()){
/**
* Get required parameters from the web form for the request
*/
$paymentType =urlencode('Sale');
$firstName =urlencode($paymentInfo['Member']['first_name']);
$lastName =urlencode($paymentInfo['Member']['last_name']);
$creditCardType =urlencode($paymentInfo['CreditCard']['credit_type']);
$creditCardNumber = urlencode($paymentInfo['CreditCard']['card_number']);
$expDateMonth =urlencode($paymentInfo['CreditCard']['expiration_month']);
$padDateMonth = str_pad($expDateMonth, 2, '0', STR_PAD_LEFT);
$expDateYear =urlencode($paymentInfo['CreditCard']['expiration_year']);
$cvv2Number = urlencode($paymentInfo['CreditCard']['cv_code']);
$address1 = urlencode($paymentInfo['Member']['billing_address']);
$address2 = urlencode($paymentInfo['Member']['billing_address2']);
$country = urlencode($paymentInfo['Member']['billing_country']);
$city = urlencode($paymentInfo['Member']['billing_city']);
$state =urlencode($paymentInfo['Member']['billing_state']);
$zip = urlencode($paymentInfo['Member']['billing_zip']);
$bperiod=urlencode( $paymentInfo['Bill']['month']); ;
$bfrequency=urlencode($paymentInfo['bill']['frequency']);
$amount = urlencode($paymentInfo['Order']['theTotal']);
$currencyCode="USD";
$time22= date('Y-m-d',time());
$startdate=urlencode(date('Y-m-d',time()));
$paymentType=urlencode('Sale');
$ip=$_SERVER['REMOTE_ADDR'];
/* Construct the request string that will be sent to PayPal.
The variable $nvpstr contains all the variables and is a
name value pair string with & as a delimiter */
$nvpstr="&AMT=$amount&CREDITCARDTYPE=$creditCardType&ACCT=$creditCardNumber&EXPDATE=".$padDateMonth.$expDateYear."&CVV2=$cvv2Number&FIRSTNAME=$firstName&LASTNAME=$lastName&STREET=$address1&CITY=$city&STATE=$state".
"&ZIP=$zip&COUNTRYCODE=US&CURRENCYCODE=$currencyCode&PROFILESTARTDATE=$startdate&BILLINGPERIOD=$bperiod&BILLINGFREQUENCY=$bfrequency";
/* Make the API call to PayPal, using API signature.
The API response is stored in an associative array called $resArray */
$resArray=$this->hash_call("CreateRecurringPaymentsProfile",$nvpstr);
/* Display the API response back to the browser.
If the response from PayPal was a success, display the response parameters'
If the response was an error, display the errors received using APIError.php.
*/
return $resArray;
//Contains 'TRANSACTIONID,AMT,AVSCODE,CVV2MATCH, Or Error Codes'
}
I geting the error Subscription start date is required.