Getting date format m-d-Y H:i:s.u from milliseconds

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You can readily do this this with the input format U.u.

$now = DateTime::createFromFormat('U.u', microtime(true));
echo $now->format("m-d-Y H:i:s.u");

This produces the following output:

04-13-2015 05:56:22.082300

From the PHP manual page for date formats:

  • U = Seconds since the Unix Epoch
  • u = Microseconds

http://php.net/manual/en/function.date.php

Thanks goes to giggsey for pointing out a flaw in my original answer, adding number_format() to the line should fix the case of the exact second. Too bad it doesn’t feel quite as elegant any more…

$now = DateTime::createFromFormat('U.u', number_format(microtime(true), 6, '.', ''));

http://php.net/manual/en/function.number-format.php

A note on time zones in response to DaVe.

Normally the createFromFormat() method will use the local time zone if one is not specified.

http://php.net/manual/en/datetime.createfromformat.php

However, the technique described here is initialising the DateTime object using microtime() which returns the number of seconds elapsed since the Unix Epoch (01 Jan 1970 00:00:00 GMT).

http://php.net/manual/en/function.microtime.php

This means that the DateTime object is implicitly initialised to UTC, which is fine for server internal tasks that just want to track elapsed time.

If you need to display the time for a particular time zone then you need to set it accordingly. However, this should be done as a separate step after the initialisation (not using the third parameter of createFromFormat()) because of the reasons discussed above.

The setTimeZone() method can be used to accomplish this requirement.

http://php.net/manual/en/datetime.settimezone.php

As an example:

$now = DateTime::createFromFormat('U.u', number_format(microtime(true), 6, '.', ''));
echo $now->format("m-d-Y H:i:s.u") . '<br>';

$local = $now->setTimeZone(new DateTimeZone('Australia/Canberra'));
echo $local->format("m-d-Y H:i:s.u") . '<br>';

Produces the following output:

10-29-2015 00:40:09.433818
10-29-2015 11:40:09.433818

Note that if you want to input into mysql, the time format needs to be:

format("Y-m-d H:i:s.u")

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