use strict;
use warnings;
use utf8;
use 5.10.0;
use POSIX ();

sub localize_strftime {
    my $locale = shift;
    my $default = POSIX::setlocale(POSIX::LC_TIME);
    POSIX::setlocale(POSIX::LC_TIME, $locale);
    my $retval = POSIX::strftime(@_);
    POSIX::setlocale(POSIX::LC_TIME, $default);
    return $retval;
}
say+localize_strftime('en_US', '%a, %d %b %Y %T %z', localtime(time));