Datetime to Timestamp in milliseconds in PHP

Question

I would like to create a timestamp in milliseconds from the input '2016-03-22 14:30'. Also the timezone specified should be Australia/Sydney.

I've tried different approaches but none seem to be working.

Can anyone help me please? I'm really struggling with that.

Answer 1

Answers with * 1000 are only formatting the output, but don't capture the precision.

With DateTime->format, where U is for seconds, u for microsecond and v for millisecond:

<?php
// pass down `now` or a saved timestamp like `2021-06-15 01:03:35.678652`
$now = new \DateTime('now', new \DateTimeZone('UTC'));
// or something like:
$now = DateTime::createFromFormat('U.u', number_format(microtime(true), 6, '.', ''), new \DateTimeZone('UTC'));

// in microseconds:
$now_us = (int)$now->format('Uu');
// e.g.: 1623719015678652


// in milliseconds:
$now_ms = (int)$now->format('Uv');
// e.g.: 1623719015678

Answer 2

For those looking how to get timestamp in milliseconds from DateTime, this is what I've come up with:

$date = new DateTimeImmutable();

$timestampMs = (int) ($date->getTimestamp() . $date->format('v'));

This gets timestamp in seconds and appends milliseconds ('v' format).

https://3v4l.org/UoZsL

Answer 3

Try this it will work

<?php
$date = new DateTime('@'.strtotime('2016-03-22 14:30'), new DateTimeZone('Australia/Sydney'));

echo "Timestamp in Australia/Sydney: ".$date->format('Y-m-d H:i:sP');
echo "<br/>";
echo "Timestamp in miliseconds Australia/Sydney: ".strtotime($date->format('Y-m-d H:i:sP'));
?>

Output:

Timestamp in Australia/Sydney: 2016-03-22 18:30:00+00:00
Timestamp in miliseconds Australia/Sydney: 1458671400