You can view past and scheduled post dates in the WordPress publish date menu

When you look at the calendar that appears when you select a date to publish an article in WordPress, there are days that are marked with a dot.

These are days when you posted articles in the past, or when you have scheduled posts.

I just noticed now.

This is useful when you are considering article publish schedule.

Dates with a dot are when post is or will be published

Here is the video.