In Welsh, the word for week is wythnos, which literally means “eight-nights”. Historically, the week started and ended with night. – WTF Fun Facts
Source: https://en.wikipedia.org/wiki/Eight-day_week
WTF Fun Fact – Wythnos

In Welsh, the word for week is wythnos, which literally means “eight-nights”. Historically, the week started and ended with night. – WTF Fun Facts
Source: https://en.wikipedia.org/wiki/Eight-day_week
its same in hungarian “hetnap” meaning seven-days