the.com/boxing day

means The day after Christmas, traditionally for giving boxed gifts or bonuses to servants, tradespeople, and the poor — now mostly known for sales, leftovers, and sofa paralysis.

from Likely from the practice in Britain of opening the alms boxes placed in churches over Christmas to collect for the poor, distributed the day after. A related custom had tradesmen and servants receive a 'Christmas box' — a gift or tip — from employers and customers on this day, as thanks for a year of service. The exact origin is debated, but both threads point to boxes full of charity or gratitude, cracked open once Christmas Day itself was done.