I just discovered a bug with version 1.5, but it looks like something that could easily be fixed, hopefully.
Here's are the settings I've used which present the issue...
Post Randomly (Surprise Me: Checked)
Post up to 1 posts per day
Randomly after: 15:00
And Before: 20:00
When my posts are scheduled, they are always scheduled from 3:00AM to 8:00AM, instead of 3pm to 8pm as desired. Any PM hours I set, end up always being scheduled during their equivalent AM periods instead.
I also tried to change my own time settings in the WordPress settings to 24-hour format, but this did not resolve this issue. It looks like somewhere along the way Drafts Scheduler isn't resolving the correct AM/PM time period.
This issue occurs in WordPress 3.1.1 as well as 3.1.2.
Thanks again for a very handy plug-in!