PHP subtract month gives me wrong values [duplicate]

one dumb question!

I'm trying to develop one code who is able to subtract one month from one specific date but i'm facing an issue and i don't know how i can't solve it, the issue is:

If given date was 2023-05-31 and i subtract one month, instead of given me the 2023-04-30, the code shows 2023-05-01.

I just want to know how i can solve it without any workaround, because if i input one date 2023-05-28 the code must showned me 2023-04-28, any ideas?

My code below:

$date = '2023-05-31';
echo date('Y-m-d', strtotime($date . ' - 1 months')); // 2023-05-01

Thanks!

source https://stackoverflow.com/questions/76221456/php-subtract-month-gives-me-wrong-values