In Polish we have "niedziela" and "poniedziałek" but etymology is not so obvious because we don't use the word "dělat" as often. We have "działać" (to act) but "robić" has a closer meaning to Czech "dělat". I would think about "dzielić" (to divide) too.
In Czech this connection is much more obvious.
neděle - den, kdy se nedělá - the day of no work
pondělí - from "po neděli" - the day after Sunday
úterý - from old Czech "vterý" which means "druhý" - the second day after Sunday
středa - from "střed (týdne)" - the middle (of the week)
čtvrtek - from "čtvrtý den" - the fourth day after Sunday
pátek - from "pátý den" - the fifth day after Sunday
sobota - from Hebrew shabbat (sabbath)
The point is that the Czech "V neděli nedělám." is ambiguous as to whether it means every Sunday or just this Sunday.
If you want to be more specific, you can say "Tuhle neděli nedělám" for not working this Sunday.
"O nedělích nedělám" or "V neděli nikdy nedělám" would specifically mean every Sunday.