DateTimemilli

gistfile1.txt

class DateTimemilli { ... }              #<=== predeclare unfinished class

#| declare operator multi in outer scope since this is where you want to use it
multi sub infix:«>»(DateTimemilli:D $a, DateTimemilli:D $b --> Bool:D)   #<=== use magic brackets
{
    say $a; 
    say $b; 
    return False;
}

#| I think delegation is a better model here https://docs.raku.org/language/objects#Delegation
#| Otherwise you have to catch millisec in 'new' constructor and redispatch to parent
class DateTimemilli {
    has Int $.millisecond;

    has DateTime $!dt handles *;        #<== so yep this handles all the methods except your overrides

    multi method TWEAK {
        my $second = $!millisecond / 1000;

        $!dt = DateTime.new(date => Date.new('2023-12-24'),    #<== maybe an Instant would be better than DateTime
                         hour => 0,
                         minute => 0,
                         :$second,              #<== pass it your value
                         timezone => 1); 
    }   

    method gist()
    {   
        self.Str~":"~$.millisecond.Str;
    }   

}

my $start = DateTimemilli.new( millisecond => 2000 );
my $end   = DateTimemilli.new( millisecond => 3000 );

say $start > $end;

#-------

#DateTimemilli<5862950986640>:2000
#DateTimemilli<5862950988032>:3000
#False