It seems that your case has been a common issue. I ran into this myself a while back and after a lot of digging, I found a similar case and an issue tracker, which shows that you all have had the same problem.

You can try this approach as a workaround, which is highlighted on the issue trackers's comment #87: you need to use a complex type for the logical date/timestamp field.

Also, it's a good idea to comment on the issue tracker to let the team know that the behavior is still causing confusion for developers. The more people who report it, the more likely they are to improve the documentation or behavior.