@Randy *******
they let you in the building at 5:30 am and that's when you can sit in the 200+ chairs they have running down next to immigrations
BUT
There usually aren't many people in Section J <- which is the section where they'd go if they're getting a 30 day extension on a tourist visa they bought before they showed up here.
I think they could show up at about 7;30-8 and be fine, without a super long queue in that section ONCE they open the immigration office doors as let the several hundred people in to the office