Adding one microsecond to Datetime object in PHP

Question

I need to add a microsecond to a Datetime object in PHP. I am trying to do it adding a time interfal a fraction of a second to the Datetime but it is not working.

$date = new Datetime('2018-06-05 09:06:46.7487');
$date->add(new DateInterval('PT0.00001S'));
echo $date->format('Y-m-d H:i:s.u');

I am not able to accomplish it though i think it should be simple. How can i add fractions of a second to a Datetime?

Mier

Tried this for versions older than 7.1? #10600882 - was added in 7.1 though if you're running. – Obsolesce

Note that PHP doesn't support microseconds in php versions lower than 7.1. I don't know which one you are on, but this might just be it. 3v4l.org/6lfO5 – Pushkin

If you're using PH < 7.1 you can't(without hacking your way thru it at least). As of PHP 7.1 you can, using modify. – Gilstrap

so no option for 7.0.30-0ubuntu0.16.04.1? – Mier

@Mier Check out my updated answer – Pharmacology

@Andrew You have to hack your way thru in PHP >= 7.1 anyways since microseconds are buggy :-( – Pharmacology

Answer 1

PHP >= 7.1 - works but there's a bug!

If you have PHP 7.1 or later then this should do it:

$date = new Datetime('2018-06-05 09:06:46.7487');
$date->modify('+1 microsecond');
echo $date->format('Y-m-d H:i:s.u');

Output:

2018-06-05 09:06:46.748701

Caution: this fails for .999999

$date = new Datetime('2018-06-05 09:06:46.999999');
$date->modify('+1 microsecond');
echo $date->format('Y-m-d H:i:s.u');

Output:

2018-06-05 09:06:46.1000000

---

PHP >= 5.2.0 "hack" but not buggy!

If you have PHP 7.0 or earlier then you can extract the microseconds and perform the math yourself in a "hacky" way:

$date = new Datetime('2018-06-05 09:06:46.7487');

// Use bcadd() to add .000001 seconds to the "microtime()" of the date
$microtime = bcadd( $date->getTimestamp().'.'.$date->format( 'u' ), '.000001', 6 );

// Reconstruct the date for consumption by __construct
$date->__construct(
    date( 'Y-m-d H:i:s.', explode( '.', $microtime )[ 0 ] ).explode( '.', $microtime )[ 1 ]
);

echo $date->format('Y-m-d H:i:s.u');

Output:

2018-06-05 09:06:46.748701

---

The hacky solution also works if the microsecond is at .999999

$date = new Datetime('2018-06-05 09:06:46.999999');

// Use bcadd() to add .000001 seconds to the "microtime()" of the date
$microtime = bcadd( $date->getTimestamp().'.'.$date->format( 'u' ), '.000001', 6 );

// Reconstruct the date for consumption by __construct
$date->__construct(
    date( 'Y-m-d H:i:s.', explode( '.', $microtime )[ 0 ] ).explode( '.', $microtime )[ 1 ]
);

echo $date->format('Y-m-d H:i:s.u');

Output:

2018-06-05 09:06:47.000000

Pharmacology

While the code is elegant, this adds 10 microseconds, and won't work if the time is later than x.999998 – Acculturation

@Acculturation I think +1 microsecond is buggy when it comes to .999999, see my edit. – Pharmacology

Note that this bug was fixed in PHP 7.2. – Kid

Answer 2

Update PHP 8.4

The new getMicrosecond and setMicrosecond methods are now available on both DateTimeImmutable and DateTime classes in PHP 8.4 and later versions.

class DateTime {
// ...
   public function getMicrosecond(): int {}

   public function setMicrosecond(int $microsecond): static {}
// ...
}

Here the getMicrosecond() method returns the microsecond part of the datetime as an integer and the setMicrosecond() method accepts an integer value to set the microsecond part of the datetime.

So to add a microsecond to a Datetime object in PHP 8.4 or later versions, the following code works.

$date = new Datetime('2018-06-05 09:06:46.7487');
$microseconds->getMicrosecond();
$microseconds = $microseconds+1;
$date->setMicrosecond($microseconds);
echo $date->format('Y-m-d H:i:s.u');

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