新的 DateTime 不能与未来的日期一起正常工作

Question

I am trying to calculate the differences between 2 dates.

The first date is the reservation date, and the second date is the traveler's birthdate. Format of the $tour_day is 15 December, 202X

$date1 = new DateTime($bir_day);
$date2 = new DateTime($tour_day);
$interval = $date1->diff($date2);

if( ($interval->y <= 8 && ($interval->m > 12 || $interval->d > 31)) || ($interval->y < 8) ){
// error: Adults must be at least 8 years old
 }

It works if the reservation date is the current year.

However if the reservation date is 2022 or more, than it cannot calculate correctly because

$date2 = new DateTime($tour_day);

is always converts as 2021.

echo $tour_day; 

is '15 December, 2023' But

echo $date2->format('m-d-y');

is '12-15-21' however it must be '12-15-23' (12-15-23 is what I want but it shows 12-15-21)

I do not understand why the future date (next year or more) is not converting correctly but the current year of any date is no problem.

Answer 1

that's because your date string is not in proper format as required by DateTime , use createFromFormat() as:

...
$tour_day = "5 December, 2023";
// your format is "Day Month, Year", so use that format as below
$date2 = DateTime::createFromFormat("j F, Y", $tour_day);
echo $date2->format('m-d-y'); // 12-05-23
...