Like a lot of us using Live Writer. Sometimes we need to use the “Set publish date” feature. Like for blogging something that happened a few days ago, when we was away from are PC’s. Just at the moment there’s a small bug in Live Writer that the team are aware of, and are working on. This causes the “Set publish date” feature, not to set the date and time. When you publish a post where you have set the publish date on.
A workaround for this is:
- Publish your post as per-normal, don’t worry about the “Set publish date”
- Then re-open that post. By clicking on it from “Recently posted” from the right of the Live Writer window.
- Set the publish date with the Date and Time you need for the post.
- Publish the post again. This time the publish date and time will be correctly set on your space.
I hope this workaround helps you out. While the Live Writer team fix the little bug. 
