I schedule about 99% of my posts. If I'm doing two posts that day, the first goes up at 7:30 AM central time and the other goes up at 5:30 PM central time. I've noticed the last three days that my posts are not posting as scheduled.
Being the crafty techno guy that I am (I am NOT that guy), I finally went to the Blogger forum and noticed a thread of other bloggers having the same issue.
The good news is that it's been reported up the chain of command to "Google Engineers". That sounds important. Hopefully they'll get it fixed soon.