Post meta as array looks like string instead of array

Question

I want to insert an array into a post meta, but something strange is happening. What am I missing here?

How I insert meta to a post:

// 1st Quarter
for ($month = 1; $month <= 3; $month++) {

  $last_day = cal_days_in_month(CAL_GREGORIAN, $month, $year);
  $first_date = strtotime("$year-$month-$first_day 00:00:00");
  $last_date = strtotime("$year-$month-$last_day 23:59:59");

  $month_dates = array(
    'name' => 'P' . $month . '-FY' . $year,
    'start_date' => date('Y-m-d', $first_date),
    'end_date' => date('Y-m-d', $last_date),
    'closed' => 0
  );
  array_push( $tmp_period, $month_dates );

} // end for

$quarter_name = 'Q1-FY' . $year;
add_post_meta( $post_id, '_q1_name', $quarter_name, true );
add_post_meta( $post_id, '_q1_subs', $tmp_period, false );

How I check the inserted meta:

$subs = get_post_meta( $post->ID );

echo '<pre>';
print_r( $subs, false );
echo '</pre>';

What the inserted meta actually looks like:

Array
(
    [_q1_name] => Array
        (
            [0] => Q1-FY2018
        )

    [_q1_subs] => Array
        (
            [0] => a:3:{i:0;a:4:{s:4:"name";s:9:"P1-FY2018";s:10:"start_date";s:10:"2018-01-01";s:8:"end_date";s:10:"2018-01-31";s:6:"closed";i:0;}i:1;a:4:{s:4:"name";s:9:"P2-FY2018";s:10:"start_date";s:10:"2018-02-01";s:8:"end_date";s:10:"2018-02-28";s:6:"closed";i:0;}i:2;a:4:{s:4:"name";s:9:"P3-FY2018";s:10:"start_date";s:10:"2018-03-01";s:8:"end_date";s:10:"2018-03-31";s:6:"closed";i:0;}}
        )
)

What I originally expected the meta to look like:

Array
(
    [_q1_name] => Array
        (
            [0] => Q1-FY2018
        )

    [_q1_subs] => Array
        (
            [0] => Array (
                   'name' => 'some name',
                   'start_date' => some start date',
                   'end_date' => some end date,
                   'closed' => some value
            ),
            [1] => Array (
                   'name' => 'some name',
                   'start_date' => some start date',
                   'end_date' => some end date,
                   'closed' => some value
            ),
            [2] => Array (
                   'name' => 'some name',
                   'start_date' => some start date',
                   'end_date' => some end date,
                   'closed' => some value
            ),
        )
)

Answer 1

Your data will be serialized, if you save non-scalar values (e.g. array, object) as post meta. You must unserialize it:

$subs = get_post_meta( $post->ID );
$subs['_q1_subs'][0] = unserialize($subs['_q1_subs'][0]);