Today is Tuesday. Yesterday was Monday. Day before was Sunday. How far back can you go for that to still be accurate and tracked by some cultures, even if it was in a different language?
This is one of my favorite answer I've written for this site:
The short answer is for more than 2,500 years, but how much more is unclear. The days didn't have the current names and associations (SAT(urn's) DAY, the SUN DAY, the MO(o)N DAY, etc) until a little bit later, so you could also argue it only dates back a little more than 2,100 years.