A simpler problem is months. The English system uses arbitrary names, while Japanese/Chinese/Korean just call them "1-month", "2-month", etc. Even though I grew up with it, I find the English system impenetrable. Quick, what's 3 months before November? I have to count it out every time. (In mod 12, -3 is the same as +9, so I just count forward 9 months.) The names of the months are a nice nod to our Roman history but…
The funny thing is that other Slavic countries use similar names but some are moved 1 month back or forth because flowers bloom earlier/later there :)
And days of the week are simply numered starting with sunday = "niedziela" (not working day), "poniedziałek" (after not working day), "wtorek" (secondary day), "środa" (middle day), "czwartek" (fourth day), "piątek" (fifth day) and "sobota" (sabbath).
I never remember the names of the roman months and have to count them starting from january.