php从epoch ms获取日期

Question

I have a field in ms from epoch, like 1350393140000. I need to, in PhP, get this field as a datetime, change the time portion of it to 7AM (UTC time) and convert it back to ms from epoch. How can I do this?

Answer 1

$input = 1350393140000;

$dt = new DateTime('@' . floor($input / 1000));
$dt->setTimeZone(new DateTimeZone('UTC'));
$dt->modify('07:00');

$output = $dt->format('U') * 1000;