Quick answer
To get unix timestamp with IntlDateFormatter class. Use this code.
$formatter = new IntlDateFormatter(
'fr_FR',
IntlDateFormatter::FULL,
IntlDateFormatter::FULL,
'Europe/Paris',
IntlDateFormatter::TRADITIONAL
);
echo $formatter->parse($formatter->format(strtotime('now')));
It seems that the only way to get timestamp from this class is only use IntlDateFormatter::parse() method.
Timestamp
Timestamp is always measured in the number of seconds since the Unix Epoch (January 1 1970 00:00:00 GMT) whatever functions or classes you use to get it. Example time(), mktime(), DateTime::getTimestamp().
Get timestamp from specific date/time.
In this example, assume that my server php.ini timezone is Asia/Bangkok and you get this date/time in Asia/Macau.
// server php.ini timezone is Asia/Bangkok
// set the date/time input.
// assume that it is Asia/Macau timezone.
$datetime = '2025-03-12 15:34:26';
$timestamp = strtotime($datetime);
echo $timestamp.'<br>';// 1741768466
// if you use function `date()`, the result will be wrong! because the timestamp is incorrectly parse using server timezone.
echo 'use date(): ' . date('Y-m-d H:i:s P', $timestamp) . '<br>';// 2025-03-12 15:34:26 +07:00 WRONG! incorrect timezone.
// even if you use `\IntlDateFormatter()` class, with or without set timezome the result still be wrong!
$formatter = new \IntlDateFormatter(
'en',
\IntlDateFormatter::FULL,
\IntlDateFormatter::FULL,
new \DateTimeZone('Asia/Macau'),
\IntlDateFormatter::GREGORIAN,
'yyyy-MM-dd kk:mm:ss ZZZZZ'
);
echo $formatter->format($timestamp).'<br>';// 2025-03-12 16:34:26 +08:00 WRONG! time does not matched.
$formatter->setTimeZone(new \DateTimeZone('Asia/Macau'));
echo $formatter->format($timestamp).'<br>';// 2025-03-12 16:34:26 +08:00 WRONG! time does not matched.
All the example above is wrong because the timestamp is parsed base on server timezone (php.ini).
Get time stamp in correct timezone.
As @Álvaro González commented, you can use strtotime('date/time timzone'); to get timstamp in certain timzone but you can also use \Datetime() or \IntlDateFormatter classes.
Example:
// server php.ini timezone is Asia/Bangkok
// set the date/time input.
// assume that it is Asia/Macau timezone.
$datetime = '2025-03-12 15:34:26';
$timestamp = strtotime($datetime . ' Asia/Macau');
echo $timestamp .'<br>';// 1741764866
echo 'use date(): ' . date('Y-m-d H:i:s P', $timestamp) . '<br>';// 2025-03-12 14:34:26 +07:00 CORRECT! but time zone is Bangkok as specified in php.ini (-1 hour for Macau to Bangkok).
$formatter = new \IntlDateFormatter(
'en',
\IntlDateFormatter::FULL,
\IntlDateFormatter::FULL,
new \DateTimeZone('Asia/Macau'),
\IntlDateFormatter::GREGORIAN,
'yyyy-MM-dd kk:mm:ss ZZZZZ'
);
echo $formatter->format($timestamp).'<br>';// 2025-03-12 15:34:26 +08:00 CORRECT!
// use `DateTime()` class to get timestamp in certain timezone.
$date = new DateTime($datetime, new \DateTimeZone('Asia/Macau'));
$timestamp2 = (int) $date->getTimestamp();
echo $timestamp2.'<br>';// 1741764866
$formatter = new \IntlDateFormatter(
'en',
\IntlDateFormatter::FULL,
\IntlDateFormatter::FULL,
new \DateTimeZone('Asia/Macau'),
\IntlDateFormatter::GREGORIAN,
'yyyy-MM-dd kk:mm:ss ZZZZZ'
);
echo $formatter->format($timestamp2) . '<br>';// 2025-03-12 15:34:26 +08:00 CORRECT!
// use `\IntlDateFormatter()` class to get timestamp in certain timezone.
$formatter = new IntlDateFormatter(
'en-US',
IntlDateFormatter::NONE,
IntlDateFormatter::NONE,
new \DateTimeZone('Asia/Macau'),
IntlDateFormatter::GREGORIAN,
'yyyy-MM-dd kk:mm:ss'
);
$timestamp3 = (int) $formatter->parse($datetime);
echo $timestamp3 . '<br>';// 1741764866 CORRECT!
To get timestamp from \IntlDateFormatter() class, you have to set the pattern in constructor matched the date/time source format.
Convert date/time across timezone
In this example I'll convert date/time result across timezone based on date/time that have got from Asia/Macau timezone.
I will use IntlDateFormatter() class to convert.
// server php.ini timezone is Asia/Bangkok
// set the date/time input.
// assume that it is date/time from Asia/Macau timezone.
$datetime = '2025-03-12 15:34:26';
$tsmacau = strtotime($datetime . ' Asia/Macau');// 1741764866
$formatter = new \IntlDateFormatter(
'en',
\IntlDateFormatter::FULL,
\IntlDateFormatter::FULL,
new \DateTimeZone('Asia/Macau'),// timezone for input timestamp.
\IntlDateFormatter::GREGORIAN,
'yyyy-MM-dd kk:mm:ss ZZZZZ'
);
// convert to Asia/Bangkok timezone.
$formatter->setTimezone(new \DateTimeZone('Asia/Bangkok'));
echo $formatter->format($tsmacau).'<br>';// 2025-03-12 14:34:26 +07:00
// convert to Europe/Paris timezone
$formatter->setTimezone(new \DateTimeZone('Europe/Paris'));
echo $formatter->format($tsmacau).'<br>';// 2025-03-12 08:34:26 +01:00
In this case you must know the timezone of timestamp because you have to set the input timezone into class constructor and change the timezone you want to convert into before call to format().
