I tried the following...
$timestamp = time();
$date_time_array = getdate($timestamp);
$hours = $date_time_array["hours"];
$minutes = $date_time_array["minutes"];
$seconds = $date_time_array["seconds"];
$month = $date_time_array["mon"];
$day = $date_time_array["mday"];
$year = $date_time_array["year"];
// use mktime to recreate the unix timestamp
// adding 19 hours to $hours
$timestamp = mktime($hours + 6, $minutes,$seconds ,$month, $day,$year);
$timetemp = date ("Y-m-d h:i:s",$timestamp);
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But it does not work because my data type in the database is DATETIME... anybody knows how to get around this