Type:
Date Start, expiration date.

Table: prefix_surveys
` startdate` data e hora padrão NULL,,
`expira` data e hora padrão NULL,

Tks,

$idSurvey = 156696;

$parametros = [
'startdate',
'expires'
];

$datainicio = '2019-09-06 08:00:00';
$datafechar = '2019-09-07 18:00:00';

$datesSurvey = $limeSurvey->get_survey_properties($idSurvey, null);

$datesSurvey = $datainicio;
$datesSurvey = $datafechar;

$datesSurvey = $limeSurvey->set_survey_properties($idSurvey, $datesSurvey);
$datesSurvey = $limeSurvey->get_survey_properties($idSurvey, null);