The Day of the Week Undies. The Day of the Week Undies is a Truly Me clothing set released in 2020. Retail cost is $28. Briefs This article (or section) is a stub. You can help American Girl Wiki by expanding it. Retrieved from "https://americangirl.fandom.com/wiki/Day_of_the_Week_Undies?oldid=96328" Categories: Article stubs Just Like You Modern Clothing Accessories Undergarments Items Released in 2020 Community content is available under CC-BY-SA unless otherwise noted.