Failed to parse time string zulu time

Question

when trying to parse a date-time (Zulu) with Carbon, I get the following error:

$t = '2021-06-01T21:29:55.155257426Z';
$r = Carbon::parse($t)->setTimezone('UTC');
dd($r);
Could not parse '2021-06-01T21:29:55.155257426Z': DateTime::__construct(): Failed to parse time string (2021-06-01T21:29:55.155257426Z) at position 0 (2): The timezone could not be found in the database

However, if I remove the last 3 digits, everything works fine, e.g.:

$t = '2021-06-01T21:29:55.155257Z';
$r = Carbon::parse($t)->toDateTimeString('microsecond');
dd($r);
"2021-06-01 21:29:55.155257"

I'm not sure what to do to parse the microseconds when I have 9 digits (.155257426Z). Any help is appreciated. Thank you.

Answer 1

PHP's DateTime, which underpins Carbon, can only handle fractional seconds up to six digits.

The following will trim it down to six at most:

function trim_nanoseconds($t) {
    return preg_replace_callback(
        '/\.(\d+)(.*)$/',
        function($a){
            return sprintf('.%s%s', substr($a[1], 0, 6), $a[2]);
        },
        $t
    );
}
$t = '2021-06-01T21:29:55.123456789Z';

var_dump(fix_nanoseconds($t));

Output:

string(27) "2021-06-01T21:29:55.123456Z"