Description:
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If I create a new DateTime object with different timezone and then try to get Unixtimestamp ('U'), I always get timestamp of my current timezone.

Test script:
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// UTC+5
$date = new DateTime( 'now', new DateTimezone( 'Asia/Yekaterinburg' ) );
echo $date->format( 'U' ) . "\n";

// UTC+3
$date = new DateTime( 'now', new DateTimezone( 'Europe/Moscow' ) );
echo $date->format( 'U' );


Expected result:
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1284734980
1284727780

Actual result:
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1284727780
1284727780