Where does “Йомабай” come from?

Йомабай (Bashkir) comes from Bashkir йома, from Arabic جُمْعَة — week.

Ancestry of “Йомабай”, step by step

Йомабай traces back through two separate lines of ancestry.

via Bashkir йома

StepLanguageWordMeaning
1BashkirйомаFriday
2Arabicجُمْعَةweek

via Bashkir бай

StepLanguageWordMeaning
1Bashkirбайrich, wealthy; rich man; "component forming given...
2Proto-Turkic*bāyrich
Every word from Arabic جُمْعَة →Every word from Bashkir йома →