End of month method doesn't consider leap year.

[takumi-dev]

Hi, I am working with this library for my product. It is awesome.
Now, I found an issue with leap year.

This is a test code.

$now = new \Moment\Moment('2016-01-31', 'Asia/Tokyo');
echo $now->subtractDays(1)->addDays(1)->startOf('day')->cloning()
->startOf('month')->addMonths(1)->setDay('30')->subtractMonths(1)->endOf('month')->format();
//It shows "2016-02-28T23:59:59+0000"
//expected is "2016-02-29T23:59:59+0000"

This will only happen when I set TimeZone at first.
If I didn't set TimeZone at first, it will not happen.

I used hack like this.

$now = new \Moment\Moment('2016-01-31', 'Asia/Tokyo');
echo $now->subtractDays(1)->addDays(1)->startOf('day')->cloning()
->startOf('month')->addMonths(1)->setDay('30')->subtractMonths(1)->endOf('month')->endOf('month')->format();
//call endOf('month') twice.
//It shows "2016-02-29T23:59:59+0000"

Thanks.

[fightbulc]

Hey Takumi. Will take a look asap. Also, are u able to add a Japanese translation?

[takumi-dev]

Hi fightbulc, I've made a translation.
I will be glad if it helps you.

Thanks for your developing.

[fightbulc]

@takumi-dev, I hope you don't do all these transformations you put up there as your test code. Do you have a real-world example where you don't get the expected result?

[takumi-dev]

@fightbulc, Sure. So far no problem for my product.
I just call endOf('month') twice. I don't know why it works, but it works.

Here is a real-world example.

$rows = array();

$start = '2016-01-31';
$end = '2016-04-30';

$timezone = 'Asia/Tokyo';
$subjectFormat = __('for %s～%s');
$dateFormat = __('Y-m-d');

$now = new \Moment\Moment($start, $timezone);
$until = new \Moment\Moment($end, $timezone);

$now->subtractDays(1);
$noDate = false;
while( $now->isBefore($until) )
{
    $now->addDays(1)->startOf('day');
    $next = $now->cloning()->startOf('month');
    if( (string)$now->getDay() === '01' )
    {
        $next->endOf('month');
        if( $noDate )
        {
            $next->setDay($until->getDay());
            $noDate = false;
        }
    }
    else
    {
        $next->addMonths(1)->setDay($until->getDay());
        if( $next->getDay() !== $until->getDay() )
        {
            $next->subtractMonths(1)->endOf('month');
        }
        if( $next->cloning()->endOf('month')->format() === $next->format() )
        {
            $noDate = true;
        }
    }

    $subject = sprintf($subjectFormat, $now->format(__('m/d')), $next->format(__('m/d')));
    $rows []= $subject;

    $now = $next;
}
print_r($rows);

/*
*  expected: Array ( [0] => for 01/31～02/29 [1] => for 03/01～03/30 [2] => for 03/31～04/30 )
*  real:     Array ( [0] => for 01/31～02/28 [1] => for 02/29～03/30 [2] => for 03/31～04/30 )
*/

These codes are for generating rows of a document for kind of estimation.
usage:
for 01/31-02/29 $100
for 03/01～03/30 $150