This has happened to me twice now, and it's irritating as hell.
I have a template all set up and ready to go. I want to schedule it for tomorrow at a particular time.
When I click on the date and the little calendar pops up, it is difficult to get it to set the proper date. Quite often, when I attempt to set the time, the date is reset to today, sometimes after I'm dead certain I've already set the date in the future.
The first time this happened, I chalked it up to user error.
The second time, it started sending an email that was prepared as a FOLLOW UP for later this week. It was meant to be a second email. The first email has not gone out yet, and I can't take those back, so now I look kind of stupid. I was absolutely certain I set the date to the proper day. But now it's happily sending them, and in the list, the date says today.
This is the most serious bug I have encountered. It would be less of an issue if manually entering the date was an option, but it's not. We're forced to use a tool that only works sometimes.