PHP Converting ASCII Date/Time Stamps to Unix Times With Microseconds

Question

I have two ASCII date time stamps. Ultimately I want to get the difference in seconds and milliseconds. I've tried using the DateTime class, as well as the Date() function. Both of these seem to truncate the microseconds, even though the docs for date formats say the class keeps it.

Here's what I've got so far:

<?php
// test.datetimediff.php

echo "<pre>\n";

$tz = new DateTimeZone('America/Toronto');
echo print_r($tz, true) . "<br>\n";

/*
$dt1 = date('Y-m-d H:i:s.u', '2013-09-30 13:06:56.944');
$dt2 = date('Y-m-d H:i:s.u', '2013-09-30 13:06:56.979');
*/

$dt1 = new Datetime('2013-09-30 13:06:56.944', $tz);
$dt2 = new Datetime('2013-09-30 13:06:56.979', $tz);

echo print_r($dt1, true) . "<br>\n";
echo print_r($dt2, true) . "<br>\n";

$interval = $dt1->diff($dt2);

$seconds = $interval->format('%s');

echo 'seconds: ' . $seconds . "<br>\n";

echo "</pre>\n" . "<br>\n";

ASCII is a character-encoding scheme, no idea what an "ASCII date" is — , Sep 30 '13 at 19:28
Pretty sure DateTime doesn't account for fractions of a second. — Sammitch, Sep 30 '13 at 19:30
@dev-null-dweller: thanks for the link to the bug. I think I've got a workaround below. — NotoriousWebmaster, Sep 30 '13 at 19:56

NotoriousWebmaster · Answer 1 · 2013-09-30T20:01:50.033

Couldn't find a function which would take microtime into account. So I converted it to straight integer seconds, and tacked on the milliseconds myself. Here's the function I set up:

/*
expects $datetime in format yyyy-mm-ddThh:mm:ss.9999
*/
function strtomtime($datetime) {

    $dt1 = strtotime($datetime);
    $pos = strrpos($datetime, '.');
    $mtime = $dt1 + floatval(substr($datetime, $pos));
    return $mtime;
}

Bogdan · Accepted Answer · 2013-10-01T18:36:53.357

This is a possible workaround. Not the prettiest, though it does the job:

<?php
// test.datetimediff.php

echo "<pre>\n";

$tz = new DateTimeZone('America/Toronto');
echo print_r($tz, true) . "<br>\n";

/*
$dt1 = date('Y-m-d H:i:s.u', '2013-09-30 13:06:56.944');
$dt2 = date('Y-m-d H:i:s.u', '2013-09-30 13:06:56.979');
*/

$dt1 = new Datetime('2013-09-30 13:06:56.944', $tz);
$dt2 = new Datetime('2013-09-30 13:06:56.979', $tz);

echo print_r($dt1, true) . "<br>\n";
echo print_r($dt2, true) . "<br>\n";

$interval = $dt1->diff($dt2);

$seconds = (int) $interval->format('%s');

// Get microseconds from both start and end date
$us1 = $dt1->format('u');
$us2 = $dt2->format('u');

// Compute the microsecond difference and add it to the seconds
$seconds += abs($us2 - $us1) / 1000000;

echo 'seconds: ' . $seconds . "<br>\n";

echo "</pre>\n" . "<br>\n";

@NotoriousWebmaster The code from the answer was meant to be a snippet you can integrate into your code to add the microseconds. I've updated the answer so you can see where it would go — Bogdan, Oct 01 '13 at 18:38

PHP Converting ASCII Date/Time Stamps to Unix Times With Microseconds

2 Answers2