Black Friday, the Friday after the Thanksgiving holiday, once marked the start of the holiday shopping season. In recent years, though, the event has begun to feel like something of a bygone tradition. The holiday retail calendar begins a little earlier every year, but 2021 was especially notable: Some retailers started dishing out early-bird sales and reminder emails as early as September. Shoppers were encouraged to order their gifts as soon as possible or risk having packages arrive late, due to rampant supply chain disruptions and mailing delays. Even books (yes, books!) weren�t safe from the impending shortages.