PHP timestamps

From timestamp to UTC

The @ prefix creates a date from Unix seconds. DateTimeImmutable leaves the original object unchanged when its time zone is changed.

<?php
$date = new DateTimeImmutable('@1711972800');
echo $date->format('Y-m-d\TH:i:sP');
// 2024-04-01T12:00:00+00:00

Display the time in Paris

$paris = $date->setTimezone(new DateTimeZone('Europe/Paris'));
echo $paris->format('Y-m-d\TH:i:sP');
// 2024-04-01T14:00:00+02:00

From date to timestamp

$date = new DateTimeImmutable('2024-04-01T14:00:00+02:00');
echo $date->getTimestamp(); // 1711972800

// Current timestamp in seconds
echo time();

Millisecond input

For this positive-value example, use a 64-bit integer and preserve the fraction with U.u. The u format expects six digits of microseconds.

$ms = 1711972800123;
$seconds = intdiv($ms, 1000);
$micros = ($ms % 1000) * 1000;
$date = DateTimeImmutable::createFromFormat(
    'U.u', sprintf('%d.%06d', $seconds, $micros)
);
if ($date === false) {
    throw new RuntimeException('Invalid date');
}
echo $date->format('Y-m-d\TH:i:s.uP');

Validate input before converting it. getTimestamp() returns whole seconds and cannot preserve microseconds by itself. The division example above is intended only for positive timestamps.

References

PHP — compound formats · createFromFormat

Open the converter

English version published September 26, 2026.