It's April 9th -- the one day of the year I'll put up with looking at the Confederate flag.

The Confederates used several different flag designs -- finding something that used familiar iconography without being confused with the Union flag, especially in poor visibility, was a challenge. But on April 9, 1865, a Confederate officer carried this flag as he approached Grant's lines.

https://americanhistory.si.edu/collections/object/nmah_515980

https://www.history.com/articles/when-did-the-white-flag-become-associated-with-surrender