system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did we decide that Saturday and Sunday would be our weekends and not any other days?
gpt
In the Judaism religion the Sabbath is the day of rest and seventh day of the week. Since Judaism was the precursor of Christianity they took that over. And since the European civilization was mostly formed around the Christian traditions and their colonies in the Americas, Australia and Africa as well, they all took the Sunday as the resting day.

It isn't until earlier in the 20th century that the Saturday wasn't  a normal working day any more and as such Saturday and Sunday became the weekend.