I can't get report parameters to work in PHP. Are they supported? This is what I am using:

PHP 5.5.36 Latest PHP ADK download. OS X/Apache

$query = "SELECT tblJobs.seqNo as JobNumber,
tblDetails.RecID as DetailID,
rate,
vendorID,
firstName,
lastName,
fullrankname,
NameCaps,
permID,
cellPhone,
tblUsers.RecID as User_ID,
address,
city,
state,
zip,
rank,
detailName,
manager,
from_UTC(from_unix_timestamp(startDate)) as startDate,
from_UTC(from_unix_timestamp(endDate)) as endDate,
hoursWorked,
subpay2,
holidayRate,
invoiceComments,
submittedDate,
monthname(sDate) as reportPeriod
from tblJobs, tblUsers, tblCompanies, tblDetails
WHERE startDate BETWEEN $P(startDate) AND $P(endDate)";

$report = vproject_make_new_report_with_datasource($project, 'Weekly_Summary', $datasource, $query);
$report.SetParameterValue("startDate", $startTimeStamp);
$report.SetParameterValue("endDate", $endTimeStamp);