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<?php $array = [ [ 'date' => '2017-12-20', 'name' => 'test A', 'kwa' => 'kwa1, kwa2' ], [ 'date' => '2017-12-20', 'name' => 'test B', 'kwa' => '' ], [ 'date' => '2017-12-21', 'name' => 'test C', 'kwa' => 'kwa1' ], [ 'date' => '2017-12-22', 'name' => 'test D', 'kwa' => '' ], [ 'date' => '2017-12-22', 'name' => 'test E', 'kwa' => '' ], ]; $result = []; foreach ($array as $result[$d][] => ['date' => $d]); var_export($result);

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