Bug in subMonth

[cmachu]

Code:

$date = [
'now' => Carbon::parse('2016-03-30'),
'prev_month' => Carbon::parse('2016-03-30')->subMonth()
];

return:

[now] => Carbon\Carbon Object
    (
        [date] => 2016-03-30 00:00:00.000000
        [timezone_type] => 3
        [timezone] => Europe/Warsaw
    )

[prev_month] => Carbon\Carbon Object
    (
        [date] => 2016-03-01 00:00:00.000000
        [timezone_type] => 3
        [timezone] => Europe/Warsaw
    )

for other months work correctly.

[EselDompteur]

same issue here

Carbon::now('Europe/Berlin')-toDateTimeString() => 2016-03-30 20:11:31
Carbon::now('Europe/Berlin')->subMonth()->toDateTimeString() => 2016-03-01 20:11:31

Workaround:

Carbon::now()->startOfMonth()->subSecond()->startOfMonth() => 2016-02-01 00:00:00

regards

[lybc]

I met the same question

today is 2016/3/31

$startTime = new Carbon('this month first day') // echo 2016-04-01

$now = Carbon::createFromDate(2016, 3, 1);
$last3Month = $now->subMonth(3);
$last2Month = $now->subMonth(2); 
$lastMonth = $now->subMonth(1);

Carbon\Carbon Object
(
    [date] => 2015-09-01 16:17:30.000000
    [timezone_type] => 3
    [timezone] => Etc/GMT-8
)
Carbon\Carbon Object
(
    [date] => 2015-09-01 16:17:30.000000
    [timezone_type] => 3
    [timezone] => Etc/GMT-8
)
Carbon\Carbon Object
(
    [date] => 2015-09-01 16:17:30.000000
    [timezone_type] => 3
    [timezone] => Etc/GMT-8
)

[davidianbonner]

Experiencing the same issue here. It happens with addMonth as well.

It appears the bug lies with php's DateTime and not Carbon. The Carbon::addMonthand Carbon::subMonth method directly use DateTime::modify.

A simple workaround to avoid this:

$nextMonth = (new Carbon($date))->endOfMonth()->addDay()->startOfDay();
$prevMonth = (new Carbon($date))->startOfMonth()->subDay()->endOfDay();

[dannyweeks]

I think the problem is deeper than this as I am having issues with even creating the correct object.

Carbon::createFromFormat('Y-m', '2016-02');
// or
Carbon::create(2016, 2, null, null, null, null, 'Europe/London');

The above returns an object of 2016-03-02;

Adding the first day of the month fixes the issue.

Carbon::create(2016, 2, 1, null, null, null, 'Europe/London');

[lucasmichot]

Everyone,
this is related to the fact that there was a change of time (winter time to summer time) on this period. This is the way \DateTime works too.
It's a bit tricky sometimes so I always take the dst flag into consideration and use the ...Month(s)NoOverflow functions as a workaround.

[lucasmichot]

Can it be closed @cmachu ?

[cmachu]

Yeap, thanks !

[gerfin]

what i fixed it by add "->subDay(3)",becaue february is 2-3 days less than other months.
for example:
what i want:
Carbon::now()->subMonth()->endOfMonth()
fixed it by:
Carbon::now()->subMonth()->subDay(3)->endOfMonth()

[kylekatarnls]

Don't do that, if you're january the 1st, then you will get the end of november.

Simply do: Carbon::now()->startOfMonth()->subMonth()->endOfMonth()