How do I change the order of my blog posts within a specific blog?

Related to this, I've tried switching between "chronological" and "reverse", but this seems to have no effect, possibly because the two posts I've made to one of my b2 blogs were posted on the same day (which begs the question of whether b2 uses dates or time stamps - if the latter, something is not working here).

Either way, I simply want to decide what order my blog posts are in. I see there's an "order" field, but entering integers in those fields appears to have zero effect. What have I missed?