Blogger vs WordPress Blog

If you want to just change the date go to the All Posts screen. Go to the WP-Admin dashboard (https://jaimiesjoyfulstampin.wordpress.com/wp-admin/)

Click on Posts ->All Posts. You will get a list of all your posts. Hover the mouse over a post title and you'll see the options to Edit and Quick Edit. Click on Quick Edit, change the date in the appropriate area, and click update.

See: https://en.support.wordpress.com/posts/edit-posts-screen/#quick-edit