Once you set the assignment Due Dates (and optional Release Dates), you might want to see exactly how these dates will appear to your students.
If your SimUText does not use Course Sections, you can see the dates simply by logging in to the SimUText Application. (Installation instructions are available here.)
If your SimUText does use Course Sections, you would be assigned to the first section that you created during your SimUText setup, and you would only be able to see the Due Dates and Release Dates for that particular section when you log into the SimUText application.