Highly Notorious Monsters

[Abhayaa]

I think most of us are arguing against long windows. I personally think long spawn times are okay.
It's having to stand there for several hours that creates the greatest sense of lost time.

Teleport out, wait 15 minutes, get claim or don't, teleport back, move on.

I think if you broke it into 6 or 8 hour spawns you could have one falling roughly in every prime-time time zone. (for the larger HNMs)

The purpose of the 3 hour window on 24hr HNMs in ffxi was so that it would rotate through time zones as the week progressed.