ELI5 Thanksgiving - why a Thursday, and why does it affect plumbers?

Why is it called Black Friday? Why is thanksgiving always on a Thursday? Did Macys invent the thanksgiving parade? Why is American Football a thanksgiving tradition? Why is the weekend after thanksgiving the busiest day in the year for plumbers? ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: optoomistic, jcd1974, buddythebear, and cjk_exstream To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter: https://www.twitter.com/eli5ThePodcast/ or send us an e-mail: [email protected]