It was also tradition in Holland !
Friday Fish Day and Wednesday Meat Day.

Wednesday was actually the day that people ate minced meat. And this all had to do with the butchers and their work rhythm.

Butchers received new animals every Monday. These were slaughtered at the same time on Monday and on Tuesday the most beautiful parts of the animal were removed. The well-known remains of the carcass were then processed into minced meat on Wednesday. The women at home stood in line (literally) for a fresh bowl of minced meat. But without a refrigerator in the house, the ground meat had to be consumed immediately. So Wednesday is Meat Day.