I got the error invalid argument supplied end date

using php and curl for AirlineFlightSchedules parameter used to get the data but show the Error Parsing Arguments – Invalid argument ‘end_date’ supplied. if i pass the wrong date format than why not give error on start end i used this format for date
both these format correct or wrong plz help
$time = strtotime(date(“m/d/Y”,time()+(86400*3)));

$time2 = date(“m/d/Y”,time()+(86400*10));

$queryParams = array(
‘start_date’ => 1500055500,
‘end_date’ => 1500055500,
‘origin’ => ‘LHE’,
‘destination’ => ‘KHI’,
‘airline’ => ‘’,
‘flightno’ => ‘’,
‘exclude_codeshare’ => ‘false’,
‘howMany’=>‘10’,
‘offset’=>‘0’

);