What do you think is the meaning of "before the end of the week"? Before Friday night or before Sunday night?
The Japanese sentence literally means "before the weekend", so it means before Friday night.

I think the meaning is slightly ambiguous and only the context will make it clear. If you are working in a business which is open from Monday to Friday, then "the end of the week" is Friday afternoon. If the business is open on Saturday, then Saturday will be the end of the week.

Then there are cultural/religious problems about which day is the beginning or the end of the week. In Judaism and Christianity the 7th day is Saturday, so Sunday is the first day. Most printed calenders in English show Sunday as the first day.

This sentence was translated from French and French is ambiguous although they nowadays also use the word "weekend". Even so, weekend and end of the week may mean different things in different cultural contexts. In France high school students would get Thursday afternoon off but they had classes on Saturday morning. So their actual "weekend" would start later, but it was still the end of the week.

Thank you. I added a more literal translation that perfectly matches your explanation and unlinked the previous Japanese translation. Perhaps someone who knows Japanese can re-translate it using "weekend".

> Most printed calenders in English show Sunday as the first day.
I know it, but...

> In Judaism and Christianity the 7th day is Saturday, so Sunday is the first day.
I didn't know this. I thought Sunday was the seventh day because God rested on the seventh day.

Christians are as confused as anybody else about which day is the day of rest. Here is a Wikipedia article about Sunday. http://en.wikipedia.org/wiki/Sunday