I found some php version get your dateDiff not correctly about chinese-calendar

[overtrue]

Plz make a PR.

[nior2insect]

Sorry sir, it's my fault.

I go find some reason and I found this *****The answer is timezone + normalize

https://stackoverflow.com/questions/40354442/why-does-php-datetime-diff-depend-on-time-zones

/************* Here I test to see date_diff by random timezone ******************/

    $tzlist = DateTimeZone::listIdentifiers(DateTimeZone::ALL);
    shuffle($tzlist);
    for($i=0;$i<10;$i++){
        $this->printDiff($tzlist[$i], date_format($date, "Y-m-d"), '1900-01-31');
        echo "<br>";    
    }

/********** Here is result ********************/

America/Indiana/Petersburg
Year: 91 Month: 06 Day: 01 days: 33420

Pacific/Tongatapu
Year: 91 Month: 06 Day: 01 days: 33419

Africa/Kigali
Year: 91 Month: 06 Day: 02 days: 33420

Australia/Currie
Year: 91 Month: 06 Day: 02 days: 33420

Europe/Monaco
Year: 91 Month: 06 Day: 01 days: 33419

UTC
Year: 91 Month: 06 Day: 02 days: 33420

PRC
Year: 91 Month: 06 Day: 01 days: 33419

Asia/Shanghai
Year: 91 Month: 06 Day: 01 days: 33419

/********************************************************/

The answer for me is when $calendar->makeDate I have to set timezone that I use.

Your code is work perfectly.

Thanks you

Stack Overflow

Why does php datetime diff depend on time zones?

See the following code:

function printDiff($tz) {
$d1 = new DateTime("2015-06-01", new DateTimeZone($tz));
$d2 = new DateTime("2015-07-01", new DateTimeZone($tz));
$diff = $d1->diff...

[overtrue]

OK, Thanks.