Currently support p is with timezone type 3 or type 2 "UTC" or explicit "Z" https://php.watch/versions/8.0/date-utc-p-format :)

<?php

date_default_timezone_set('Europe/Berlin');
$date = new \DateTime('2023-01-25T00:00:00');
echo $date->format('p');

?>

For missing offset is default offset:
Expected result: +01:00
For explicit offset +00:00
Expected result: +00:00
Or !localtime
a6e3ce4#diff-975ac482adc74b487c6ac9d8dde32153e4b8a803ef8ec41e8d6594f0a042db69R715
Expected result with p and timezone UTC
$date2 = new DateTime('now', new DateTimeZone('UTC'));
echo $date2->format('p'); // Z

@damianwadley Why did you change this to "Verified" — I see no triage report as to why this issue occurs, and whether this is an issue at all.

I assumed it had been verified because the "needs triage" was removed. Though I did briefly confirm that "p" wasn't outputting just Z which it's documented to do.